Sponsored by
North Carolina State University
North Carolina Agricultural Research Service
North Carolina Cooperative Extension
North Carolina Association of Nurserymen

CONTENTS

NC State University Horticultural Science
Ornamentals Work Group

Living on the Edge, Grounded in Success
Robert E. Lyons
Professor and Director: NC State University/JC Raulston Arboretum

Considering the Sites
* Naturally wet areas; inextricable impact on surrounding soils; plants often growing partially submerged.
* Natural areas, subject to flooding.
* Constructed areas, built-in moist "edges."
* Constructed areas, hard edges, little chance for overflow….purely aesthetic.
Considering the Sites
* Naturally wet areas
* Natural areas, subject to flooding, soils are not constantly wet, but often moist; plants survive occasional flooding up to 6"….."marginals"
* Constructed areas, built-in moist "edges."
* Constructed areas, hard edges, little chance for overflow…..purely aesthetic.
Considering the sites
* Naturally wet areas.
* Natural areas, subject to flooding.
* Constructed areas, built-in moist "edges;" design includes this feature intentionally.
* Constructed areas, hard edges, little chance for overflow…..purely aesthetic.
Considering the sites
* Naturally wet areas.
* Natural areas, subject to flooding.
* Constructed areas, built-in moist "edges."
* Constructed areas, hard edges, little chance for overflow, little impact on surrounding soils…..purely aesthetic need for complementary plants.
Exposure
* Sun
o Often provides the greatest number of plant choices.
o Probably the most common scenario for water gardens.
* Shade
o Is more limiting in possibilities but still quite possible.
o Good arena to select nature woodland species and cultivars thereof.
Plant Type
* Herbaceous vs. Woody…..depends on personal tastes, of course; diversity is always preferred.
* Vegetative litter due to deciduous woodies is worth considering from a maintenance perspective.
* Emphasis may also depend on this speaker’s expertise area!
Life Cycles
* PERENNIALS
o Often preferred from a cost and maintenance standpoint.
o Includes herbaceous and woody choices.
* ANNUALS
o Showing up in surprisingly greater numbers to complement water gardens.
o Tropical, non-hardy types are included here, too.
Surprising Choices from Unlikely Families
* Asclepiads
* Hibiscus
* Bulbous species
* Rudbeckias
* Iris
Noteworthy Groups
* Ligularias (Ligularia & Farfugia spp.)
* Perennial Lobelias
* "Composite Trio"; Vernonia, Eupatorium, and Solidago spp.
Selected Species
(sun is best; marginals)
* Turtleheads (Chelone)
* Obedient Plant (Physostegia)
* Bee Balms (Monarda)
* Rodgersia
* Lizard’s Tail (Saururus)
* Forget-Me-Nots (Myosotis)
Soggier Candidates
* Marsh Marigold (Caltha palustris)
* Pitcher Plants Sarracenia)
* Sweet Flag (Acorus)
* Cattails (Typha)
* Pickerelweed (Pontediera cordata)
* Golden Club (Orontium aquaticum)
Summer Shade Candidates
* Hostas
* Skunk Cabbages (Symplocarpus foetidus)
* Jack-in-the-Pulpits (Arisaema)
* Arums
* Trout Lilies (Erythronium)
* Umbrella Plant (Podophyllum peltatum)
Deciduous Woodies
(mostly shrubs)
* Buttonbush (Cephalanthus)
* Summersweet (Clethra)
* Fothergilla
* Witchhazel (Hamamelis)
* Winterberry (Ilex verticillata)
* River Birch (Betula nigra)

Inheritance is Fun:
Update on Breeding Efforts in Cercis and Stokesia
Dennis J. Werner, Jessica Gaus, Layne Snelling, Freya Hopswood, and Jeff Adkins

Department of Horticultural Science
North Carolina State University

INTRODUCTION
Breeding and genetic studies of various herbaceous perennial and woody ornamentals have been initiated at North Carolina State University. In addition to development of new ornamental cultivars, the research program has focused on other related objectives including studies of reproductive biology, genetic diversity, propagation, and inheritance of important traits in these genera.
Stokesia
Stokesia laevis (Hill) E. Greene, stokes aster, is an herbaceous perennial native to the southeastern United States. Its range is quite restricted, with scattered populations found primarily in Mississippi, Alabama, Florida, Louisiana, and Georgia. Historically, stokes aster has enjoyed moderate popularity in the perennials industry. Stokes aster is a versatile plant that thrives in a variety of climates including full sun to part shade in well drained to moderately damp soils. The flowers of stokes aster, a member of the Asteraceae family, are perfect and composite. Renewed interest in this plant has been fueled by the introduction of ‘Omega Skyrocket’, and the more recent introductions of ‘Honeysong Purple’ and ‘Colorwheel’. Both cultivars have exciting new flower colors that make great additions to any landscape.
‘Omega Skyrocket’ was derived from a wild population of stokes aster demonstrating unique architecture discovered in central Georgia. This population, now lost due to agricultural use of the site, was discovered in Colquitt County, GA, near the town of Omega by Ron Dieterman of the Atlanta Botanical Garden. Plants in this population showed tall, upright flowering scape architecture, unlike the shorter, non-upright scapes typical of the species. ‘Omega Skyrocket’ has lavender-blue flower color typical of the species. Our initial breeding objectives have focused on incorporating the novel upright scape architecture into a broader range of flower colors. Accordingly, we have hybridized ‘Omega Skyrocket’ with cultivars ‘Alba’, ‘Mary Gregory’, ‘Peaches Delight’, and ‘Purple Parasols’, demonstrating white, yellow, violet, and deep violet flower color, respectively. First generation hybrid plants (F1 progeny) in all crosses demonstrate both violet-blue flower color and upright growth architecture characteristic of ‘Omega Skyrocket’, suggesting genetic dominance of these characters. Second generation (F2) plants have been obtained from all of these crosses. To date, we have recovered various interesting progeny that have potential as commercial cultivars. These progeny, as well as advanced selections from other hybrid combinations, will be discussed.
Cercis
The high number of interesting genetic variants in Cercis canadensis offers a number of exciting breeding opportunities. Traits of interest include red leaf color (‘Forest Pansy’), leaf variegation (‘Silver Cloud’), double flowers (‘Flame’), white flowers (‘Alba’), pink flowers (‘Withers Pink Charm’), violet-red flowers (‘Appalachian Red’), weeping growth habit (‘Traveller’ and ‘Covey’), purple fruit color (some accessions of Cercis canadensis var. mexicana), and glossy foliage (Cercis canadensis var. texensis). We have made hybridizations in numerous combinations between these taxa. The different F1 families have been established in isolation blocks at the Sandhills Research Station in Jackson Springs, NC for production of genetically pure F2 seed. This presentation will summarize our program objectives, and progress made in the breeding program to date.

Scintillating Shrubs: Camellias, Lilacs and other Fletcher Finds
Dick Bir and Joe Conner

Thanks to sustained support from NCAN and occasional support from others, we have been evaluating plant performance at MHCRS, Fletcher for decades. You have probably heard Dick talk about our work with deciduous hollies, forsythia, hydrangeas, monarda, phlox, roses, etc. somewhere over the past years. If you have not and have internet access, please go to the following website http://fletcher.ces.state.nc.us/staff/rbir/. Much of the information has been summarized there.
Our work has always been with replicated trials of plants on their own roots, i.e., no grafts. With the luxury of time and space that does not exist at other university facilities, our trials have been focused on plants growing in the ground year-round for multiple years. They are subjected to the wet and dry years as well as the warm and cold winters.
Camellia: Trials have included both allegedly hardy cultivars and breeder numbered selections as well as many plants identified by an accession number from plant collection expeditions. Numbered plants will not be discussed here since most of them were either not hardy or are unlikely to ever make it into the nursery trade.
Our evaluations were based both on floriferousness and winter injury. We had a subjective scale for winter injury with 10 indicating dead plants and 0 being no damage on any plant of that cultivar. The most common form of injury was a marginal leaf burn or leaf scorch with occasional tip dieback. Our site is tough . . . full sun for much of the day on an exposed hillside at 2200 ft. elevation. One camellia fancier told us that ours was not a fair test for garden camellias. Our response is that we want truly hardy camellias for the mountains and for shipping to the more northern market. Our best plants should be considered for a protected USDA Hardiness Zone 6 site or a more exposed Zone 7a. Temperatures did not go below 0 F. during our trials. Following a low of 5 F. last winter, the floral display for late winter and early spring 2003 flowering cultivars was spectacular.
Based on these trials we do NOT recommend the following: ‘Anticipation,’ ‘Daintiness’ and ‘Winter’s Fancy’ failed to survive. ‘Paulette Goddard,’ ‘Barbara Clark’ and ‘Debbie Jury’ displayed significant damage. ‘Egao,’ ‘Pink Fragrance,’ ‘Jury’s Yellow’ and ‘Nicky Crisp’ showed less winter injury but did not flower consistently.
Cultivars that displayed no more than light winter injury despite the challenging conditions were: ‘Rendezvous,’ ‘Winter’s Fire,’ ‘Twilight Glow,’ ‘Donation,’ ‘E. G. Waterhouse,’ ‘Snow Flurry,’ ‘Winter’s Star,’ ‘Winter’s Waterlily,’ ‘Winter’s Charm,’ ‘Carolina Moonmist,’ ‘Winter’s Beauty,’ ‘April Kiss,’ ‘April Dawn,’ ‘April Rose,’ ‘Spring Song,’ ‘Pink Butterfly’ and ‘Ryuko.’ Almost impervious to winter injury were ‘Spring’s Promise,’ ‘Winter’s Interlude,’ ‘Pink Icicle,’ ‘April Blush,’ ‘April Remembered’ and ‘Snow Man.’
Attracting the most late winter attention were Camellia Forest Nursery’s April Series along with ‘Donation’ and ‘E. G. Waterhouse’ for sheer numbers of flowers and ‘Pink Icicle’ for size, vigor and numbers of flowers. Among the fall flowering types, ‘Pink Butterfly’ and ‘Carolina Moonmist’ attracted attention along with the ‘Winter’ series from the US National Arboretum.
Lilacs: Trials have been ongoing for 20 years. Objectives have been disease and insect resistance as well as garden worthiness. Our hope is that we will find cultivars that will perform well across North Carolina. In 2003 we have had lilacs in bloom continuously since mid April and, if you count the tree lilacs, they will be in bloom well into June. In the mountains, all the common lilac, Syringa vulgaris, hybrids . . . lilacs that look and smell like what most folks want lilacs to be . . . grow well. Those reported to be mildew free actually are nearly mildew free in our trials. However, most of the common lilacs eventually had borer problems and required significant pruning. ‘Wedgewood Blue,’ ‘Miss Ellen Wilmott’ and ‘Albert Holden’ have been among our favorites.
The small leaf lilacs have shown good performance in the piedmont as well as at Fletcher but they do not ‘look and smell’ like lilacs. Among these,
Syringa microphylla ‘Superba,’ Syringa meyeri ‘Palibin’ and Syringa ‘Tinkerbelle’ have shown spectacular bloom and should be considered on their own merits rather than being compared with common lilac. They were all in bloom by mid to late April in 2003 and held their flowers well despite heavy rains, some hail and snow.
The late flowering lilacs are also abundant producers of flowers. The colors are spectacular but this group has also suffered the drawback of not looking or smelling like common lilacs. For us, Preston hybrids ‘Miss Canada’ and ‘Redwine’ performed well in shades of pink and red while the Korean lilac, Syringa patula ‘Miss Kim’ flowers a consistent light violet.
We’ve come to the conclusion that our best hope for a lilac across the state will be a hybrid. Fortunately, there is a hybrid group with parentage including the common lilac and a very early bloomer Syringa oblata. In fact, S. oblata consistently tried to flower in March when we had it in trials . . . and the petals froze 9 out of the 10 years we had it. In the piedmont it fares much better. The S. oblata cultivars ‘Betsy Ross’ and ‘Cheyenne’ are definitely worth trying but were not in our trials.
The most promising group of hybrids is generally labeled as Syringa x hyacinthiflora. Some of the best-known plants in this group are referred to as Descanso hybrids for the Southern California garden that introduced them. Canadians tend to call this group American lilacs while in the U.S. growers tend to call them Canadian lilacs. S x hyacinthiflora are also often called early lilacs because they bloom before common lilacs in much of the U.S. and Canada. However, they bloom at about the same time as common lilacs in the Asheville area. ‘Angel White’ has been reported to perform well as far south as Tifton, GA and also does well for us. ‘Mt. Baker’ is a slightly better white under our conditions. Both are terrific. Seeing differences in the shades of blue and purple is a challenge for Dick. ‘Excell’ and ‘Evangeline’ are among the earliest to flower for us . . . their flowers wearing snow this year. ‘Asessippi’ is slightly later and similarly pigmented. Choose any of the three if you want a lilac-colored lilac flower. ‘Blue Skies’ is slightly bluer while our favorite reddish purple is fragrant ‘Pocahontas.’ A cultivar we see as pink is ‘Lavender Lady’ but we prefer ‘Maiden’s Blush’ for a more lilac-like fragrance, delicate pink flowers and growth habit.
We’ve tried many more, but the cultivars we have mentioned have been the best performers under our conditions . . . so far. If there is a conclusion, it is that in the mountains and upper piedmont of NC you can grow most lilacs if you pay attention to their culture. As you get into warmer parts of North Carolina, look towards the little leaf types and the Syringa x hyacinthiflora hybrids.
None of our lilac research would have been possible without the generosity of NCAN as well as the following nurseries: Bailey, Carlton Plants, Knight Hollow, Monrovia, Spring Meadow, Syringa Plus and numerous gardens that shared a rooted cutting or species seedling just so we could watch them grow.

Vegetative Annuals: The Emerging Backbone of Seasonal Landscape Color
Robert E. Lyons
Professor and Director: NC State University/JC Raulston Arboretum

Selected Species
Centaurea gymnanthera ‘Colchester White’
Pennisetum setaceum ‘Rubrum’ (annual purple fountain grass)
Pennisetum ‘Burgundy Giant’
Strobilanthes deyeranus (Persian shield)
Ipomoea batatas ‘Sweet Caroline’ series
Lantana camara
Lantana camara ‘Samantha’ (Variegated lantana)
Lantana trifolia
Solenostemon scutallerioides (Coleus!)
Salvia officinalis ‘Purpurea’
Salvia officinalis ‘Icterina’
Alternanthera dentata ‘Rubiginosa’
Alternanthera ficoidea (Red Thread)
Alternanthera ficoidea (snow Queen)
Plectranthus argentatus (silver shrub)
Plectranthus ‘Athens Gem’
Plectranthus ‘Limelight’
Plectranthus ‘Nicolleta’
Petunia ‘Color Splash’
Abelmoschus esculentus ‘Burgundy’ (purple okra)
Orthosiphon stamineus/Clerodendranthus spicatus (cat’s whiskers)
Pachystachys lutea (yellow shrimp plant)
Justicia brandegeana/Bellaperone guttata (shrimp plant)
Sanchezia speciosa
Abutilon pictum ‘Thompsonii’
Acalypha wilkesiana
Acalypha wilkesiana ‘Obovata’
Acalypha wilkesiana ‘Petticoat’
Euphorbia tirucalli ‘Sticks of Fire’
Dalechampia roezliana (purple dove vine)
Aristolochia gigantea

Re-inventing Sweetshrubs
Dr. Thomas G. Ranney

The sweetshrubs (Calycanthus/Sinocalycanthus) are among the oldest known flowering plants with fossil records dating back to the early and mid cretaceous periods (144 – 65 million years ago). As the Age of Dinosaurs came to an end, and the supercontinent Pangea was rifting apart, these ancient plants were present and on the move, radiating out around the world.
Although the sweetshrubs are not generally considered mainstream landscape plants, they hold great promise. The sweetshubs offer fragrant flowers, attractive foliage, broad adaptability, shade tolerance, and excellent pest resistance. Once discovered, gardeners invariably become infatuated and muse romantically about the alluring fragrance and subtle charm of sweetshrubs. No garden should be without them!
The family Calycanthaceae is small and includes 3-4 genera including Chimonanthus (Asia), Calycanthus (North America), Sinocalycanthus (Asia) and Idiospermum (Austrailia). There are two species of sweetshrubs native to North America, the Carolina sweetshrub (Calycanthus floridus) and the California sweetshrub (Calycanthus occidentalis). The Chinese wax shrub (Sinocalycanthus chinensis) is a rare species native to the Zheijang Province in southeast China and is more closely related to the Calycanthus than are the other two genera.
The Carolina sweetshrub is naturally found throughout much the Eastern United States and commonly grows as an understory shrub in mixed deciduous forests, often along streams and in moist woodlands. The leaves and stems are strongly aromatic and the bark, at one time, was used as a substitute for cinnamon. Height can vary and ranges from 3 to 9 feet, growing as multi-stemmed shrubs with suckering shoots arising from the base and roots. Fall color can be an attractive buttery yellow. The flowers, however, are the main attraction. Although they may not be considered show-stoppers from a distance, the primitive upright flowers are packed with tepals that vary from reddish purple to a dark chocolate brown. The fragrance is also variable and somewhat hard to describe. Wine connoisseurs could have a heyday describing the complex aromas of strawberries and melons with subtle accents of cinnamon and spices. Others simply inhale and go ahhhhh!
The California sweetshrub is naturally found in Washington and California growing as an understory species along streams and on moist canyon slopes. Although similar to the Carolina sweetshrub, the California species is larger in most all respects with the plants growing to over 12’ tall. The flowers, though larger and a brighter red, are typically not as fragrant.
Chinese wax shrub was only recently introduced into cultivation after being distributed by the Shanghai Botanical Garden in 1980. This medium-sized shrub grows to 3 to 9 feet tall with large, glossy leaves. The flowers open more completely than do Calycanthus spp. and are multicolored with the outer perianth whorl being whitish pink and the inner whorl being a strong yellow with occasional purple streaks at the base. Unfortunately, there is little fragrance. Despite its fairly southern origins, the Chinese wax shrub has proven hardy in USDA zone 5.
The Chinese wax shrub is closely related to our North American sweetshrubs. In paleobotany terms, many closely related taxa that are found in both North America and Asia, are referred to as "disjunct Tertiary relics". After Pangia fractured, with Laurasia going to the Northern Hemisphere and Gondwana moving to the Southern, Laurasia broke apart in the Tertiary period (26-66 million years ago). This disjunction separated North America from Eurasia and separated the population of plants that eventually gave rise to Calycanthus and Sinocalycanthus. Similar patterns exist for the Magnolia, Liriodendron, Cotinus, and Hamamelis.
A quick breakdown of species, varieties, and cultivars:
Calycanthus floridus (sweetshrub, strawberry-shrub, Carolina allspice, Carolina sweetshrub, spicebush). Distinguished by obovate-lanceolate to oblong-elliptic tepals, 10-20 stamens, and lateral bud partially hidden by the petiole base. There are two varieties that vary primarily in the degree of pubescence on the leaves and twigs. However, the ranges of these varieties overlap and variation in the amount of pubescence is common.
Calycanthus floridus var. floridus (Calycanthus brockianus, C. mohrii). Twigs, petiole, and abaxial surface of leaf pubescent.
Calycanthus floridus var. glaucus (Calycanthus glaucus, C. fertilis, C. floridus var. laevigatus, C. floridus var. oblongifolius, C. nanus). Twigs, petiole, and abaxial surface of leaf glabrous or with scattered trichomes.
Notable cultivars:
‘Athens’ – One of a number of yellow/green flowered forms with lustrous, dark green foliage, and excellent flower fragrance. A number of other yellow flowered, but unnamed, forms exist. Richard Weaver, formally with We-Du Nurseries, and Wyatt LeFever, with Blue Ridge Fish Hatchery, have both discovered additional yellow forms in the wilds of North Carolina. Interestingly, these yellow flowered forms were once considered to be a separate species, C. brochianus, but this treatment is generally no longer accepted.
‘Michel Lindsey’ – Introduced by Holbrook Farm and Nursery, formally in Fletcher, NC. Extremely lustrous, glossy foliage with very fragrant reddish brown flowers and yellow fall color.
‘Purpureus’ – Grown mostly in Europe. Somewhat disappointing with the underside of the leaves being only slightly purple – a trait that can be found in seedling populations of C. floridus.
Calycanthus occidentalis (California spicebush, California sweetshrub). Distinguished by linear to linear-spatulate to ovate-elliptic tepals, 10-15 stamens, and lateral buds being exposed.
Sinocalycanthus chinensis (Calycanthus chinensis) (Chinese wax shrub). Distinguished by the large leaves 16-25 cm long and 10-12 cm wide, tepals arranged in two distinct series, and whitish pink flower color with yellow inner tepals.
The New Sweetshrubs.
As reported by Lasseigne et al. (2001), Richard Hartlage, then an undergraduate student in Horticultural Science at North Carolina State Univ., performed reciprocal crosses between Sinocalycanthus chinensis and Calycanthus floridus in 1991. Four seedlings resulted, one of which appeared to be a hybrid and it bloomed 5 years later. This hybrid was later named _Sinocalycalycanthus raulstonii Lasseigne and Fantz ‘Hartlage Wine’.
In many regards, this hybrid retains the best qualities of both parents with large, maroon, wine-red flowers that open widely with a subtle fragrance and roots easily from cuttings. Once established, plants can be very floriferous and extremely showy.

_Sinocalycanthus raulstonii ‘Hartlage Wine’

Encouraged and inspired by the success of ‘Hartlage Wine’, we have been working on further developing new hybrids of Calycanthus. We have successfully developed additional hybrids between Sincalycanthus chinensis and Calycanthus floridus and new hybrids between Sincalycanthus chinensis and Calycanthus occidentalis. Although most of these hybrids are extremely infertile, we have been able to produce a limited number of advanced generation hybrids that include all three taxa. Many of these hybrids are just now blooming for the first time and the range of characteristics and the potential for new nursery crops is outstanding. We plan to introduce an exceptional new hybrid later this year named ‘Venus’.
‘Venus’ Sweetshrub
(_Sinocalycalycanthus ‘Venus’) PPAF
‘Venus’ is a complex hybrid, developed at NC State University, that includes Sinocalycanthus chinensis, Calycanthus floridus, and Calycanthus occidentalis in its pedigree. The result is exceptional. This medium-sized shrub produces large, ivory yellow buds that transform into large, magnolia-like, white flowers with yellow and purple infusions in the center. The flowers have an enticing fragrance with aromas of strawberries and melons. Flowering is primarily in the spring, though additional flowers are produced throughout the growing season. ‘Venus’ is being patented and should be available to propagators by mid-summer.

The Feasibility of Using Reference Evapotranspiration (ETo) to Estimate the Irrigation Needs of Landscapes in the Southeast
Patricia Lindsey
North Carolina State University

Meeting today’s urban water demands is increasingly challenging in the face of water shortages and periodic drought here in the southeast. As municipalities strive to conserve often limited supplies, measures are adopted that reduce or frequently restrict landscape irrigation altogether. As we continue to look for water efficient options, it is very useful to examine approaches developed over the last decade in California. Two initiatives are especially noteworthy and very applicable to the southeast:

1. As of January 1, 1993, all cities and counties in California were required to administer the State Model Water Efficient Landscape Ordinance, which required landscape professionals to:
* Group plants with similar water needs in zones with a separate irrigation valve.
* Schedule irrigations based on normal evapotranspiration (ET) adjusted by plant coefficients.
* Maintain efficient irrigation systems.
* Abide by set limits on total allowable water use.
This ordinance was supported by the Green Industry as a way to stay proactive and be an equal partner in the discussion to regulate yet stretch water supplies within the context of maintaining and preserving healthy and beautiful commercial and residential landscapes.
The ordinance resulted in the organization of an active statewide workgroup of landscape specialists and University of California researchers, whose purpose was fill the gap in the knowledge that would allow for successful implementation of the ordinance. Specifically, they were able to identify and classify over 1800 plants based on their estimated water usage and have refined a water budget formula to accurately predict landscape water use- the Landscape Coefficient Method.
The Water Budget Approach
The basis of water budgeting is evapotranspiration-based landscape irrigation scheduling. Reference evapotranspiration (ETo) data is estimated from a Class A evaporation pan or from specialized weather stations. Normal year (historical) monthly averages for four cities in NC are found in Table 2. Using ETo promotes conservation because it ensures that the landscape receives only the amount of water actually needed (or lost from the soil by evaporation and from plants by transpiration).
Water Budget Formula
= ETo x Landscape Area x Conversion Factor

Adjusted Water Budget Formula
= ETo x Crop Coefficient x Landscape Area x Conversion Factor
Where the crop coefficient is a multiplier that adjusts the reference ET value so that it more realistically represents the water use of a specific crop.
Landscape Evapotranspiration Formula
LCM- Landscape Coefficient Method (KL). The LCM utilizes the above water budget approach but substitutes a landscape coefficient for a crop coefficient. It is the equivalent of the crop coefficients used in agriculture and has been developed specifically for estimating the water requirements of landscape plantings. It accounts for differences in species, planting density and microclimate. This formula is covered in UC Cooperative Leaflet 21493 (Costello, Matheny, and Clark, 1991) and the formula is:
= ETo x Crop Coefficient x Landscape Area x Conversion Factor
Where the Crop Coefficient or adjustment factor = ks x kd x kmc
See Table 1 for the estimated values for each factor. This is an area where obviously much more research is needed. Not much is known empirically about the actual water needs of plants and how the coefficients may vary from region to region, over the course of a year, and over the lifespan of the landscape. How transferable is the California plant water use database to the southeast? Likewise, there will be considerable variation in density and microclimatic factors relative to the complexity of landscape plantings and a greater understanding of site design features and its impact on evapotranspiration will need to be studied in much greater detail.

Case Study: Using the Landscape Evapotranspiration Formula to Estimate Landscape Water Use for a Planting in Raleigh, NC.
Step 1.
Calculating the Landscape Coefficient (KL)
A well established 200ft2 bed of flowering cherry trees on the south side of a 3 story building in Raleigh that reflects light and heat throughout the afternoon and a planting of the same on the shady, cooler, north side of the building. There is no underplanting, just mulch.
KL = ks x kd x kmc
(south side) KL = 0.8 x 1.0 x 1.4 = 1.12
(north side) KL = 0.8 x 1.0 x 0.5 = 0.4Step 2.
Calculating Landscape Evapotranspiration (ETL)
ETL = KL x ETo
(south side) ETL = 1.12 x 0.22" = 0.25"(north side) ETL = 0.4 x 0.22" = 0.08"
Step 3.
Calculating the Total Water to Apply (TWA) for one day
TWA = ETL ETL = landscape coefficient
IE IE = irrigation efficiency, assume .70, sprinkler
(south side) ETL = 1.12 x 0.22 = 0.36"
TWA = 0.25"/.70 = 0.24"
(north side) ETL = 0.4 x 0.22 = 0.08"
TWA = 0.08"/.70 = 0.11"
Converting to gallons of water needed to maintain area to be irrigated (gallons = inches x area x 0.62).
(south side) TWA = 0.25"/.70 = 0.36"
0.36" x 200ft2 x 0.62 = 44.6 gallons
(north side) TWA = 0.06"/.70 = 0.08"
0.11" x 200ft2 x 0.62 = 13.6 gallons
contrast the LCM derived water usage with conventional PET or potential evapotranspiration rates for mature shade trees (.80 in a warm, humid climate (.30 PET inches/day):
TWA for entire site:
= .623 x plant area x plant factor x P.E.T (taken from regional chart)
= .623 x 200ft2 x .80 x 0.30"
= 29.9 gallons
= 29.9/.70 = 42.7 gallons or 85 gallons for both sites
LCM:
South side= 44.6 gallons (4% more than PET)North side = 13.6 gallons (73% less than PET)
58 gallons for both sites (31% less overall than PET)
Summary
The Landscape Evapotranspiration Formula ultimately has the potential to help refine and more accurately predict landscape water use requirements. This in turn may provide the Green Industry in NC and the southeast with greater ability to influence policies on water planning and management as conservation and regulatory approaches are developed and implemented.

Species Factor (ks):Orchard values range from 0.56 to 1.12 in summer
Assume landscape trees can lose less than potential maximum and be healthy
Density Factor (kd):
60-100% canopy cover is considered average, kd =1.0
If surface evaporation is not controlled, increase kd by 10-20%
Microclimatic Factor (kmc):
An "average" microclimate is one in which site features such as buildings, structures, pavements, slopes, surface reflectivity do not influence the microclimate, kmc =1.0
In "high", site features greatly increase evaporative conditions, kmc = 1.0-1.4
In "low", site is shaded, protected from winds, north facing, kmc = 0.5-1.0 Table 2. NORMAL EVAPOTRANSPIRATION DATA FOR NORTH CAROLINA (INCHES)
MONTH Asheville Charlotte Raleigh Wilmington
January 0.5 1.95 2.01 2.1
February 0.63 2.44 2.44 2.64
March 1.35 4.07 4.0 4.21
April 2.65 6.04 5.81 6.35
May 4.33 7.16 6.38 7.31
June 5.83 7.63 6.87 7.24
July ) 6.36 7.64 6.89 7.53
August 5.76 7.06 6.25 6.4
September 4.11 5.45 4.88 5.34
October 2.4 3.87 3.56 4.0
November 1.03 2.7 2.71 2.86
December 0.56 2.07 2.15 2.39

Organic Fertilizers for Basil Transplant Production
Michelle McGinnis, Al Cooke, Ted Bilderback, and Mary Lorscheider

Basil is a top-selling retail herb during the spring and early summer months. Some markets may be willing to pay a premium for basil grown under organic conditions. Vermicompost or worm castings is often used as a sustainable soil amendment by organic growers for transplant production, and the literature shows that the use of worm castings can have positive effects on root development and growth, plant development, and field crop yield.
This project was initiated to evaluate the use of worm castings as a substrate amendment with five commercial organic fertilizers. We were interested in container life of the organic fertilizers, effects of the fertilizers on pH, and whether a worm castings amendment affected the behavior of the organic fertilizer.
Basil seeds (Osimum basilicum ‘Genovese’) were sown into 98-plug trays with a peat-based substrate amended with 10% worm castings on August 15, 2002. Seedlings were grown with no fertilization, and upon the development of the first set of true leaves were transplanted into the fertilizer treatments. The basil seedling plugs were transplanted into ITML 4.5-inch geranium pots (4.5-inch diameter, 3 7/8-inch high, 37 cu. in.) with 11 fertilizer treatments and 7 replications per treatment on September 5, 2002. Treatments included 5 organic fertilizers with and without commercial worm castings (Vermicycle Organics) and one treatment with worm castings but no additional fertilizer.
The substrate was a commercial blend of peat, perlite, vermiculite, and pine bark to which additional perlite was added resulting in the following volumetric analysis for the basic substrate: Peat 38.7%, Perlite 38.0%, Vermiculite 11.6%, and Pine bark 11.6%. For the vermicompost amended substrate, worm castings were blended into the basic substrate resulting in Peat 34.9%, Perlite 34.2%, Vermiculite 10.5%, Pine bark 10.5%, and Worm castings 10%. The following treatments were created by mixing the indicated amount of fertilizer with either the basic substrate or the vermicompost substrate. The fertilizers were incorporated at a rate of 1.2 g N/pot:
EHO Espoma Holly-tone 4-6-4 (30 grams)
EHW Espoma Holly-tone 4-6-4 (30 grams) with worm castings
EPO Espoma Plant-tone 5-3-3 (24 grams)
EPW Espoma Plant-tone 5-3-3 (24 grams) with worm castings
FSO Fertrell Super 3-2-3 (40 grams)
FSW Fertrell Super 3-2-3 (40 grams) with worm castings
N1O Nature Safe 8-5-5 (15 grams)
N1W Nature Safe 8-5-5 (15 grams) with worm castings
N2O Nature Safe 10-2-8 (12 grams)
N2W Nature Safe 10-2-8 (12 grams) with worm castings
WCW media with worm castings (no additional fertilizer)
The potted basil plants were set outside in the nursery in a completely randomized block and watered in. Plants were hand watered as needed. Starting on September 10, 2002, pour-thru tests were conducted, and EC and pH measurements were obtained for randomly selected plants for a period of 6 weeks. A composite leachate sample for each treatment was collected at the first time point, September 10, and submitted to the North Carolina Department of Agriculture’s Agronomic Lab for analysis.
Endpoints measured are growth index, fresh weight, dry weight, number of fully formed leaves, and number of lateral shoots. The growth index was calculated by the following:
[([(max width + min width) / 2] + height) / 2 ] final - [([(max width + min width) /2 ] + height) / 2] initial
Nutrient leachate analyses 5 days after pot up indicate the highest concentrations of N, P, K, Ca, Mg, S, Mn, Zn, B, and Cl in one or both of the Espoma Holly-tone treatments (EHO or EHW). The highest Cu and Na concentrations were found in the Espoma Plant-tone with worm castings treatment (EPW).
All treatments had high levels of nitrogen, however the Espoma Holly-tone treatments (EHO and EHW) had the highest concentration of total inorganic nitrogen, indicating the nitrogen in this fertilizer was fast-releasing in our conditions. Ammonium was detected in the samples from all fertilizer treatments, nitrate was detected in the Espoma Holly-tone treatments (EHO and EHW), the worm castings only treatment (WCW), and in the Nature Safe fertilizers with worm castings (N1W and N2W). Urea was detected in the Nature Safe and Fertrell Super treatments (N1O, N1W, N2O, N2W, FSO, and FSW) as well as the Espoma Plant-tone with worm castings (EPW).
The pH readings for both Fertrell Super treatments (FSO and FSW) had the highest pH measurements, as the only treatments with measurements above 7.5 at the first time point (9/5/03) and the last time point (10/14/02).
A significant difference for fresh weight was found for N1W above all other treatments. Significant differences for dry weight, growth index, and number of fully formed leaves was found for N1W and N2W above all other treatments. FSO, FSW, and WCW consistently rated significantly lower on the above referenced endpoint measures. No distinct significant differences between the treatments were noted for number of side shoots. EHW was not included in that statistical analysis due to small sample size cause by a high mortality rate, believed to be caused either by transplant stress or high salt content.
In conclusion:
* Nutrients from Espoma Holly-tone (EHO and EHW) released rapidly under our conditions.
* The Fertrell Super treatments (FSO and FSW) appeared to cause undesirably high pH under our conditions.
* Depending on desirable endpoints, economics, and/or logistics, Espoma Plant-tone (EPO and EPW), Nature Safe 8-5-5 without castings (N1O) and Nature Safe 10-2-8 without castings (N2O) yielded saleable plants.
* The addition of worm castings to the Nature Safe treatments (N1W and N2W) showed a significant difference with respect to growth index, number of fully formed leaves, fresh weight, and dry weight.

Integrated Pest Management in the Nursery
Christine Casey
Department of Entomology, NCSU

Management of insect and mite pests in the nursery has been quite a challenge for North Carolina growers in recent years. New problems such as the Asian ambrosia beetle have appeared, while traditional pest control products have left the market or become more restricted in their use or availability.
WHAT’S NEW IN NURSERY IPM?
Recent changes will have a significant impact on how we manage pests in the nursery. Resistance management labeling now mandates pesticide rotation. So it is no longer legal to use repeated applications of a single product to control a persistent pest such as spider mites. Growers need to plan ahead so that they have an adequate supply of the appropriate pesticides on hand.
Legislative changes are leading to the replacement of many traditional pesticides with new materials that often work quite differently. The whitefly product Endeavor is a good example. This is a pesticide that does not kill insects. Instead it acts against whiteflies and aphids by paralyzing their mouthparts so they cannot feed and thus starve to death. While feeding stops in about an hour, mortality may take several days. In some cases these new products will not have the same efficacy or will be more expensive. In the past, for example, chlorinated hydrocarbons (e.g. lindane) or organophosphates (e.g. dursban) could be used to provide reliable, long-term borer control. As these products have been removed from the market they have been replaced by the more expensive pyrethroids.
The continued popularity of perennials means that a more varied range of plant material is being overwintered in the nursery, raising the possibility of new pest introductions. Some herbaceous perennials are susceptible to the thrips-transmitted tospoviruses impatiens necrotic spot virus (INSV) and tomato spotted wilt virus (TSWV).
HOW DO I COPE WITH THESE CHANGES?
Growers will no longer be able to rely only on broad-spectrum, long-residual materials for pest management. New pesticides tend to target fewer pests and may not kill all lifestages. This means that scouting and proper pest identification will be essential for effective management. Research to develop cost-effective nursery scouting programs is underway at NC State. I am currently testing sampling plans for spider mites and lacebugs.
Many new pesticides are compatible with natural enemies, so biological control will become more important as part of nursery IPM programs. Studies in New Jersey have shown that the green lacewing predator can provide good lace bug control on azaleas when it is used in conjunction with insecticidal soap.KEY PESTS: SOME EXAMPLES
Ambrosia beetles. These beetles bore into trees, causing loss of vigor and mortality. All species carry a fungus called ambrosia that they cultivate in their galleries as a food source. The most serious is the Asian ambrosia beetle, Xylosandrus crassiusculus, which also seems to introduce plant pathogens such as Fusarium sp., leading to rapid plant death. Ambrosia beetle activity is recognized by the frass plugs they push out as they excavate their galleries. Control is based on ethanol traps to correctly time pesticide applications; Astro is the most effective product. Fortunately ambrosia beetle numbers have been quite low this spring, possibly due to the cold weather last winter.
Other borers (e.g. flatheaded and clearwinged). Legislative changes will likely result in further restrictions on persistent, broad-spectrum pesticides commonly used to control borers. This means that accurate timing of pesticide applications will be critical. Pheromone traps for clearwinged borers (e.g. ash, dogwood, peachtree, and rhododendron borer) can be used to correctly time sprays. Alternative strategies, such as weakening borers with pesticides and then using nematodes to kill them, will come into use. Merit can be used for some important borer pests (e.g. it is effective for flatheaded appletree borers but not for clearwing borers) but must be applied well in advance of the problem for adequate uptake into the plant. Unless you are certain that you will have a problem, it may be difficult to justify this expense.
Spider mites. These mites are a common pest in North Carolina nurseries, where they can cause serious damage. Development of pesticide resistance is common in mites, so rotation of pesticides and use of alternate strategies such as biological control is important. One limitation to biological control has been the time required to deliver predators such as Phytoseiulus persimilis to large numbers of plants. Use of a mechanical dispenser or other dispersal aid can overcome this.EMERGING PESTS
INSV/TSWV. These two plant viruses are already an important problem in greenhouse production, where they cause significant crop loss. TSWV infects over 900 plant species, including many herbaceous perennials. It is vectored by 5 species of thrips, 3 of which are common in North Carolina. The most common vector in ornamentals is the western flower thrips, shown in Figure 1. Weeds are an important virus reservoir, in fact regular mowing of rows to prevent weed flowering can have a significant impact on thrips levels. The host range of INSV and its vector complex are less well-known, although both are probably large. The popularity of perennials and the common practice of overwintering plants makes it likely that these will become important nursery pests. Thrips are not a pest nursery growers typically watch for but this must change if these viruses are to be properly managed. The photographs of thrips injury (Figure 2) and virus symptoms (Figure 3) give you an idea of what to look for. It is also important to monitor thrips with yellow sticky cards.

Figure 1. Female western flower thrips (actual size 1/16 inch).
Photo by C. O’Donnell, UC Davis

Figure 2. Examples of thrips injury.
Thrips injury to rose Typical flower injury Typical leaf feeding scars
Photo by J. Clark, UC IPM Photo by B. Whipker, NCSU Photo by B. Whipker, NCSU

Figure 3. Tospovirus symptoms
.
INSV infecting cineraria INSV infecting coleus TSWV infecting dahlia
Photo by B. Whipker, NCSU

Sudden Oak Death Survey and Other Disease Updates
Colleen Y. Warfield and D. Michael Benson
Department of Plant Pathology
North Carolina State University

A pilot survey of commercial nurseries in five southern states in the Appalachian region, including North Carolina, is currently underway in cooperation with the USDA. This survey is voluntary and was designed as a pilot program to gather information on the incidence and distribution of the disease known as Sudden Oak Death (SOD) or Phytophthora canker caused by the pathogen Phytophthora ramorum. This disease occurs in forests in California and Oregon; has been reported in one nursery in California and more recently in an Oregon nursery; and in nurseries in the Netherlands, Germany, the United Kingdom as well as other European countries. The recent discovery of P. ramorum infecting Pieris and Viburnum in an Oregon nursery was an uncomfortable reminder of the potential threat of this disease to the nursery industry in North Carolina. There is no current evidence that suggests this pathogen has been introduced into North Carolina or the southeastern United States. However, due to the shipment of plant material from potentially infested areas of California, Oregon and Europe the potential exists for this pathogen to be introduced into North Carolina sometime in the future.
While we do not expect to find P. ramorum in our nursery survey, we are also isolating and identifying any species of Phytophthora causing aerial dieback that we do find on the crops surveyed. This information, together with the data obtained from the four other southeastern state surveys, should enable us to determine the predominant species of Phytophthora affecting nursery crops in this region of the country. Knowing the occurrence of Phytophthora species in specific geographic regions will help to identify pathways that this fungus may using in order to spread across both native habitats as well as state borders. In addition, identification of specific Phytophthora species may have important implications in the future management of Phytophthora diseases. Data is currently being generated, but a trend has begun to emerge which suggests that high levels of fungicide resistance to mefenoxam (Subdue MAXX) are being observed within certain species of Phytophthora.
The symptoms caused by P. ramorum are not unlike those observed for the more common Phytophthora species found in nurseries. One key difference is that P. ramorum has thus far only been found to infect the aerial parts of plants including the leaves, green and woody stems, but not the roots. Preliminary studies in California have shown that a film of water on the leaves must be present for a minimum of 12 hours in order for leaf (in this case, bay laurel) infection to occur. Temperatures in the 15-20∞C range were most favorable for spore production. Therefore, we are probably more likely to see symptoms caused by P. ramorum during the early spring months in North Carolina, as opposed to late spring and early summer as would be more typical with the common Phytophthora species.
Today we will discuss the symptoms associated with this pathogen, modes of pathogen survival, and steps you can take to help minimize losses in your nursery should this pathogen be introduced.

Evaluation of Pot-in-Pot in Nursery Crop Production
Billy Carriker

Pot-in-Pot production is a fairly new concept in our area. It was first seen in North Carolina in the late1980’s. It is beginning to gain popularity among growers, but is still not widely used due mainly to the lack of information available and the tremendous amount of capital to install and start up an operation employing this technique. The reason for doing this project was to compile as much information as was available and arrange it in an understandable manner.
What exactly is Pot-in-Pot production? Pot-in-Pot, commonly referred to as PiP, was developed to combine the benefits of container production; growing in a highly managed substrate and the ability to harvest year round with ease, with the benefits of field production; insulated root zone and less water usage. This was accomplished by burying a pot, the socket pot, in the ground with about three inches protruding and placing the pot the plant will be grown in, the insert pot, inside it, hence the name pot-in-pot. All of this was developed for one main reason. When the building boom of the 1990’s hit, the size of the average newly constructed home grew by almost 1,000sqft. This caused a dramatic increase in the demand for larger plant material. Growers needed a way to grow plant material to a larger size efficiently and still be able to harvest it year round. To do this plants needed to be grown in a container, but use less water than tree boxes and large above ground containers, as well as grow quicker than conventional container produced plants. Though the building boom has begun to slow, the demand for large plant material is higher than ever.
The advantages of pot-in-pot are numerous. The most noticeable advantage is an increased growth rate. Shrubs will not only grow to a larger overall size in less time, but they will also be more filled out and have more dense foliage. In trees a similar result is noticeable. The tree will not only grow in caliper more quickly, but will grow a larger head and denser canopy in less time. Besides increased growth rate, pot-in-pot produced plants require little if any winter protection while in the socket pot. There is also no need for any type of blow over prevention or spacing of plants every year because the spacing is preset. Pot-in-pot production systems do not require any specialized harvesting equipment because harvesting is reduced to simply lifting the insert pot out of the socket pot and placing it on any type of vehicle. Aside from being able to harvest year round, pot-in-pot actually extends the growing season because it insulates the root zone. This insulated root zone causes a dramatic decrease in the amount of water that the plant needs during high temperatures compared to above ground containers. These are the main advantages of pot-in-pot that were shared by all growers in this study, but each grower also experienced other advantages unique to their system.
As there is with any type of production system there are some draw backs to pot-in-pot production. These consist of issues such as what is called blow-out, where the roots of the plant break through the insert pot and grow into the socket pot making it difficult to harvest the plant. Another disadvantage to a pot-in-pot system is that the spacing of the field is permanent. This makes crop scheduling more difficult because the grower must consider the fact that the plants can’t be moved around on the production pad. The biggest deterrent of pot-in-pot production is the cost. It costs approximately ten times as much to install a pot-in-pot field as it does a conventional above ground system. To install fifteen to twenty-five gallon pots, it cost approximately $20,000 to $25,000 per acre. This is what causes most growers to steer away from pot-in-pot, but if all other factors are considered, this high initial cost is quickly offset by all of the benefits it brings.
There is no set method for constructing a pot-in-pot field. Each grower has his own way of doing it and usually changes methods several times before completing the whole operation. Each method contains different ways of completing the same basic principles required to successfully install a pot-in-pot system. These basic functions are as follows. The growing area is laid out in the same method as it would be for an above ground area. After the perimeter is established and the orientation of the pots is decided on, the spacing of the pots must be determined. After determining the spacing of the pots each row must be marked. A trench approximately two feet deep is then dug at the location of each row and a corrugated drain pipe is placed in the trench, covered in gravel, and then filled in with soil. After the drain lines have been installed the rows need to be re-marked and the spacing within each row established. The location of each pot should be marked and then a hole the size of the socket pot is dug at each location with an auger, stopping approximately four to six inches above the drain pipe. A pair of hand held post hole diggers are then used to dig a small hole from the bottom of the large hole to the drain pipe. This small hole is then filled with gravel and forms the drain for each pot. A socket pot is then placed in each hole and backfilled. After all of the socket pots have been installed, a small trench is dug beside each row for the irrigation line. This trench only needs to be about two inches deep so many growers use a single disc to cut it. After the irrigation lines are installed a ground cloth is laid over the entire field, an "X" is cut at the location of each socket pot, and the points are folded downward into the socket pot. This is the basic method for installing a pot-in-pot field, but there are many variations that work well.
Irrigation of a pot-in-pot operation must be handled by drip irrigation. Spray stakes are employed in most situations because traditional drip emitters simply will not supply enough water to large containers. The spray stakes are placed in each pot and connected to the buried irrigation line with a spaghetti tube. Most spray stakes have an adjustment on them to control the amount of water being applied to an extent, but in large pots several stakes can be placed in the same pot to supply ample water. The advantage of using drip irrigation rather than overhead irrigation in a pot-in-pot system is that it requires significantly less water to be applied to reach the same moisture level in the growing media. There is no deflection caused by the plan’s canopy and less evaporation due to the fact that the water droplets travel a shorter distance through the air. More water can be reclaimed because any unused water travels through the pot and into the drain system. It is then returned directly to a retention basin. With overhead irrigation much of the water never enters the pot and a lot of the runoff is never reclaimed. The major disadvantage to drip irrigation is that it requires a clean water source. Silt particles can clog the narrow spaghetti tubes and spray nozzles. This can be dealt with one of two ways. For a smaller operation a well can be used to supply water to the drip irrigation system. Well water is normally clean enough not to need any filtering and works well in these systems. For larger operation where surface water must be used a filter system can be installed to clean the water. There are several types of systems on the market now but the most popular are sand filters and disc bank filters. Drip irrigation is the superior method of irrigating a pot-in-pot operation due to the more accurate placement of water.
Growing in a pot-in-pot system is very similar to growing in conventional above ground containers. Propagation and liner production are handled the same as for conventional production. After the liners have been grown to the desired size, they are transplanted into the insert pot that they will be sold in. The insert pot containing the plant is then taken to the production area and placed into a socket pot of the same size. The plant is grown in that location until it is ready to sell. It is then lifted out of the socket pot and sold. There are no special steps that must be taken to grow in a pot-in-pot system, it actually reduces the number of processes required to produce a finished plant.
Pot-in-pot production has many advantages over above ground container production. It produces a higher quality plant in less time and requires less manpower than conventional production. Pot-in-pot requires less water for irrigation and no winter protection for most plants. It does have a high initial start-up cost and requires much more labor to install than an above ground container production facility, but it quickly overcomes these disadvantages with the ability to cut production time by one-third.

Clay Substrate Amendment Saves and Pays
James S. Owen, Jr.
North Carolina State University
Department of Horticulture Science

Soilless substrate is the ‘green’ industry standard for growing ornamental plants, yet soilless substrates do not offer the nutrient retention or water buffering capacity provided by soil. Clay minerals and humic matter are the dominant soil components that provide these beneficial attributes. With little nutrient or water buffering capacity, high water and nutrient inputs are required to yield a salable plant quickly.
The majority of containerized nursery crops in the United States are grown in bark based container substrate (West Coast and Eastern United States). Pine bark, common in the Eastern United States, when combined with frequent irrigation and high fertility levels produces rapid plant growth. However, environmental concerns and water restrictions are forcing growers to rethink production practices, particularly, in regards to water and fertilizer usage. Due to pine bark’s limited water and nutrient buffer capacity, growers cannot simply reduce water or fertilizer usage without sacrificing plant growth and quality. Modifying container substrate to increase water and nutrient buffering capacity might increase water and nutrient efficiency.
Prior to 2002, there were seven research studies focused on adding clay to soilless container substrate in the United States. Of those only two looked at clay and bark combinations. The remaining five were with peat based substrate. In addition, the research done with clay in Europe was with peat. Therefore, it was not surprising that little was known about using clay in bark. Prior to 2002, the most detailed study had been conducted with arcillite (a calcined montmorillonite and illite clay) by Warren and Bilderback in 1992. Arcillite was incorporated into pine bark with rates from 0 to 136 lbs/yd3. Container capacity, available water, and bulk density increased with increasing rate of arcillite. Substrate NH4, P, and K concentrations increased with increasing arcillite rate suggesting that arcillite improved retention within the container substrate. Plant growth increased curvilinearly with arcillite rate, with maximum dry weight occurring at 112 lbs/yd3.
The value of adding clay to soilless substrates has been debated for years. Even though amending soilless substrates with clay has many potential benefits, there was little empirical evidence to answer this question. ‘Clay’ is often used generically to describe soils that have high water and nutrient holding capacity. Clays, like soils, are not the same due to differences in physical and chemical properties as a result of handling, source, and packaging. The effectiveness of clay will differ with type (2:1 versus 1:1), handling (temperature treatment, particle size), and source or location mined (chemical composition). The type of clay and heat treatment (pasteurized or calcined) are important factors affecting water holding capacity and available water content, thus determining water buffering capacity. These factors, in addition to the chemical composition and particle size, determine phosphorus retention in the substrate and availability to the plant. Phosphorus retention is a function of the abundance of exposed aluminum and iron oxides which can be a result of handling, source, and type of clay. Therefore, it is misleading to simply talk about ‘clay’ soils. Will any clay soil improve the water and nutrient capacity of a soilless substrate? That led us to begin looking at the differing types of clay, particles sizes, and heat treatments to see how these factors might affect the response of clay amended pine bark substrates.
An international research conference in 2001 re-ignited our interest in using clay as an amendment with pine bark substrates. Research conducted in the Netherlands suggested that clay as a peat substrate amendment was worth the additional cost and that particle size along with the type (2:1 and 1:1) of clay had an impact on the effect of clay.
In 2002, we examined several types of clay in combination with several particle sizes and heat treatments [calcined (~800 F) or pasteurized (~250 F)] as a pine bark amendment. Most 2:1 clays treatments increased water and nutrient buffering capacity compared to the 8 pine bark: 1 sand substrate. However, there was a wide range of results. Cumulative water applied to the substrate amended with small (24-48 mesh) or large (4-20 mesh size) particle size clay was ~ 6 and 3 gallons less, respectively, than the 8 pine bark : 1 sand substrate. This translates to 100,000 to 200,000 gallons per growing acre per season. Even though the clay amended substrates required less water, plant growth was not affected since Cotoneaster dammeri ‘Skogholm’ root and shoot dry weight were similar in all treatments. In addition to water savings, the 2:1 clays gave us increased phosphorous retention, with maximum retention being obtained from the small particle size, calcined clay amended pine bark substrate.
The increased water and nutrient buffering capacity of a clay amended pine bark substrate could allow growers more flexibility in cultural management. This could allow nurseries to incorporate best management practices (BMP's) while maintaining maximum plant growth, making the BMP's a more attainable goal.

Container-grown Herbaceous Perennials: Response to Fertility and Water
Peter Conden, Stuart Warren, and Robert Lyons

Herbaceous perennials have grown to be a major factor in nursery production over the last decade. More and more nursery owners are reaping the benefits of this fast growing, low input crop. Despite this rise in popularity, very little research has been reported regarding nutrition and irrigation requirements of perennials. Many growers follow fertilizer company recommendations or past experience in woody plant production. In an effort to establish guidelines for nutrition and irrigation procedures for production of container-grown herbaceous perennials, the following study was undertaken.
On June 1, 2002, 3 species (Hemerocallis ‘Aztec Gold’, Coreopsis grandiflora ‘Early Sunrise’, and Santolina chamaecyparissus) were potted into 1 gal containers utilizing a medium of 8 pine bark : 1 sand (by vol), amended with 2 lbs/yd3 dolomitic limestone and 0.5 lb/yd3 granular surfactant (Aqua-Gro G, Scotts Co., Marysville, OH). Fertilizer treatments were incorporated into the medium prior to potting, and consisted of a 5-6 month controlled-release (CRF) (Polyon 16N-5P-10K with minors, Harrell’s Sylacauga, AL) After potting, the plants were placed on a gravel pad at the NCSU Horticultural Field Laboratory, Raleigh. The plants were subjected to four rates of controlled-release fertilizer and four irrigation volumes delivered through individual spray stakes. The CRF treatments were 8, 11, 14, or 17 lbs/yd3 (the labeled low, medium, and high rates were 8, 12, and 16 lbs/yd3). The irrigation treatments were 40, 80, 120, or 160% of available water (AW) per container [(AW = 24 oz (720 ml)], applied cyclically at 11:00 am, 1:00 pm and 3:00 pm daily. The experimental design was a randomized split-split plot with irrigation as the main treatment, species as the split plot treatment, and fertilizer rate as the split-split plot treatment.

Results and Discussion
Fertilizer rate had no significant effect on shoot dry weight, root dry weight, or visual rating across all irrigation treatments and species. Nutrient content of plant tissue was significantly affected by irrigation and fertilizer treatment, indicating that plants were taking up nutrients up to luxury consumption levels. Nearly all plants had visual ratings of 4 or 5 out of 5, indicating a full, lush, saleable plant.
All plants except Coreopsis that received 80% available water had leaching fractions (LF) of ≈20%, which is recommended for growing woody plants (Coreopsis needed 160% available water to reach 20% LF). However, there were no few differences in growth among all irrigation treatments.
This study indicates that the labeled rates for CRFs are too high for producing saleable perennials, and water requirements are lower than we expected. This will add up to tremendous economic as well as environmental savings in terms of water and fertilizer usage. Because these results were somewhat surprising, this study will be repeated in 2003 with lower rates of fertilizer and water. The 2003 study should allow us to develop fertilizer and water recommendations for production of container-grown herbaceous perennials.

Drill and Fill and Other Field Nursery Fertilizer Application Techniques
Ted Bilderback, Carroll Williamson, Donald Breedlove, John Allen and
Mary Lorscheider

Introduction
Field grown nursery stock has traditionally been fertilized with soluble field grade granular fertilizers which are customarily applied in spilt applications as a top dress to established crops before bud break and in early summer. Nutrient availability in field grade fertilizers is subject to rainfall. Heavy rain may wash soluble nutrients away before they can be absorbed by roots. A summer drought may delay release of nutrients until late summer or fall, potentially causing a late flush and damage by early frosts or reduced acclimation and death due to winter freezing temperatures. Controlled release fertilizers (CRF’s) can also be applied as a one time per year top dress. However, growers consider CRF’s to be expensive and there is a lack of information regarding any improved efficiency or greater plant growth of field grown nursery stock.
In recent years, many field grown nursery crops have been irrigated with drip irrigation. With irrigation in place, nursery stock can be "fertigated" by injecting soluble fertilizers into the irrigation line. The annual rate of fertilizer application can be divided into several applications during the growing season. Liquid fertilizer can also be used to supplement granular field applications, particularly if rainfall has washed granular fertilizer away from plant roots.
The Drill & Fill fertilizer application technique is new in concept to field production of nursery stock. The Drill & Fill technique is very similar to the soil auger technique used for landscape shade trees by tree service companies for decades. The Drill & Fill method uses a drill or punch bar to create holes adjacent to field grown plants. CRF’s can then be placed below the soil surface, therefore less prone to wash away from plant roots or be moved by mowing equipment and other cultural activities. However, only a few grower observations provide any evidence of the benefit of this labor intensive fertilizer technique. Objectives of the study
The objectives of this study were to measure plant growth responses of test crops to Drill & Fill CRF application compared to Top Dress application of CRF; Liquid Fertilizer application distributed by the irrigation system during the growing season; dry granular fertilizer split applications and combinations of liquid fertigation, dry fertilizer surface application, Drill & Fill CRF and Top Dress CRF fertilizer application techniques.
Materials and Methods
One year in field, established plants of Ilex X ‘Nellie R. Stevens’ Holly and Ulmus parvifolia ‘Allee’ elm were selected as test crops. The study was conducted at Shiloh Nursery, Harmony, NC in cooperation with John Allen and Danny Allen owners of Shiloh Nursery. Other cooperators in the study were Donald Breedlove, Iredell County Horticulture Agent, Mary Kelly and Rick Helpingstine or Harrell’s Fertilizer Company and Ted Bilderback, Carroll Williamson and Mary Lorscheider of N.C. State University.
All plants in the study were drip irrigated. To conduct this study, 5 rows of nursery stock for each crop were selected. There were 360 ‘Nellie R. Stevens’ hollies and 360 ‘Allee’ elms included in the study for a total of 720 plants. On November 8, initial growth measurements were taken for each plant in the study. On Feb 7, 2003, each plant was measured again. ‘Allee’ elms were measured for height and caliper. ‘Nellie R. Stevens’ was measured for height, maximum width and minimum width. A growth index (GI) was calculated by averaging maximum and minimum width, adding height and dividing the sum by 2. Differences between initial measurements and data collected 15 months later were used to calculate an increase in for both test crops. Drill & Fill and Top Dressed Controlled Release Fertilizers samples were also collected Feb 7, 2003, sent to Pursell Industries, Sylacauga, Al and analyzed for percent of total nitrogen released.
Shiloh standard fertilizer practices included application of dry granular 17-17-17 before bud break in spring and application of NH4-NO3 (34-0-0) in June. Liquid fertilizer ( ) applied via irrigation lines was is used as a supplemental practice. Liquid fertilizer was applied in 5 applications during the growing season.
Controlled Release Fertilizer treatments were applied November 8, 2001 and January 29, 2002. A gas powered drill and 2 inch auger were used to create 2 holes six to ten inches deep on each side in line with the drip irrigation tubes. Eight ounces of 18-6-12 (8-9 month release) Harrell’s/Polyon fertilizer was deposited just beyond the root zone. The controlled release fertilizer was then covered with field soil. The same fertilizer product was also top dressed on each side of the plant at the same rate as Drill & Fill.Results
Analysis of release of the 18-6-12 Harrell’s/Polyon Controlled Release Fertilizer indicated that approximately 47% of the Drill & Fill and 36% of the Top Dressed CRF had released from November 8, 2001 to February 7, 2003 (Table 1). Considering that no more than one-half of the nitrogen in the controlled release fertilizers released, it would be expected that the CRF’s could influence growth during the 2003 growing season. A third follow-up measurement of growth responses in Fall 2003 would seem to be appropriate.
The amount of nitrogen fertilizer applied or released (available for plant adsorption) produced variable plant growth responses in both test crops. The combination Drill & Fill + Liquid + Dry Granular fertilizer treatment had the highest amount of fertilizer applied (6.9 oz N) and available (5.4 oz N), however ‘Allee’ elm had similar caliper in treatments with 1/3 rd the applied / available N. In contrast, for ‘Nellie R. Stevens holly, the highest rate was not among the best treatments. Additionally, there did not appear to be any preference for the fertilizer application technique. For example, the Liquid + Dry Fertilizer treatment produced the greatest increases in growth index for ‘Nellie R. Stevens’ but had one of the lowest increases in caliper for ‘Allee’ elm. No application technique used alone and/or in combination with other techniques produced the greatest growth responses in either crop. The most consistent fertilizer treatments were Dry Fertilizer, Top Dress CRF + Dry Fertilizer, and the Drill & Fill + Top Dress CRF which produced the greatest increase in growth in both species. Table 1. Summary of Treatments, Rates Applied and Available Nitrogen Per Plant
Fertilizer N Applied N Released ‘ Allee Elm’ ‘ Nellie R Stevens’
Treatment Plant/yr Plant/yr Increased Caliper Increased in GI
(oz) (oz) (mm)
Dry Fertilizer 2.0 2.0 23.7a 10.0 ab
Liquid Fertilizer 34-0-0 2.0 2.0 21.9b 9.7ab
Drill & Fill
CRF 18-6-12 2.9 1.4 23.4a 6.9bc
Top Dress
CRF 18-6-12 2.9 1.0 23.5 a 6.8bc
Liquid +
Dry Fertilizer 4.0 4.0 22.2b 10.2a
Drill & Fill +
Dry Fertilizer 4.9 3.4 22.2b 7.7ab
Top Dress CRF +
Dry Fertilizer 4.9 3.0 22.9a 8.8ab
Top Dress CRF +
Liquid 4.9 3.0 22.8a 6.7bc
Drill & Fill CRF+
Liquid 4.9 3.4 23.0a 6.9c
Drill & Fill CRF +
Top Dress CRF 5.8 2.4 25.1a 9.1ab
Drill & Fill CRF +
Liquid +
Dry Fertiizer 6.9 5.4 23.8a 7.1bc
Significance to the Industry
The Harrell’s/Polyon 18-6-12 (8-9 month) controlled release fertilizer had 47% of the N released from Drill and Fill method and 36% of the N released as a Top Dress application. Fertilizer application rate and the application technique did not provide conclusive results regarding effects on plant growth characteristics measured for either test crop. Residual growth response during the 2003 growing season is expected for the controlled release fertilizer treatments.