Master Gardenersm Column for the Week of November 14, 2005
Carol Weaver
Brunswick County Extension Master Gardenersm Volunteer
November is a good time to plant spring-flowering bulbs. Spring- and early summer-flowering bulbs must be planted in the fall to develop strong root systems and to satisfy the cold requirements of the bulbs. The soil temperature needs to be below 60°F (16°C) before planting. In our area, this temperature usually occurs in late November or early December. Here are some tips for more effectively using bulbs in your landscape.
Since soil-borne fungi more easily invade injured bulbs, avoid unnecessary injury to the bulbs before planting. Sort through the bulbs and discard any that are partly decayed. Look particularly at the neck and basal areas of the bulbs. One way to discover decayed bulbs is to place them in water. Healthy bulbs will sink, while decayed bulbs will float. The problem with this immersion detection method is that the dipping water can become contaminated with spores from decaying bulbs and thus contaminate healthy bulbs. Bulbs should be treated with a fungicide after dipping into water.
If you start with healthy bulbs, bulb diseases are generally not a problem. If the soil becomes diseased, use Terraclor (PCNB) in the bed before planting the bulbs in the fall. The major foliage disease for tulips is Botrytis or Fire Blight. It can be readily controlled by many available fungicides. Check labels for recommendations. In addition, gardeners should use crop rotation in flower beds so the soil inhabiting pathogens do not build up to high levels.
Good drainage is required for your bulbs. Be sure to take a free soil sample prior to planting your bulbs. This will help you know exactly what amendments to the soil are required. Your soil sample results will indicate what fertilizer and lime, if any, are required to provide the optimum conditions for your bulbs. The soil pH should be in the 6.0 – 7.0 range.
Excavate the area to be planted. Depths are measured from the base of the bulbs to soil level:
These depths of planting will help protect the bulbs against frost, animals, and physical damage due to hoeing or cultivating. Be certain to thoroughly loosen the soil under the bulbs.
Place the bulbs in the bed and space according to size. Large bulbs should be spaced 3 - 6 inches and small bulbs 1 - 2 inches apart.
Cover the bulbs with soil, using only one-half of the soil removed. Water thoroughly. Finish covering bulbs with remaining soil. Cover the bed with 2 - 3 inches of mulch. If the fall is dry, water area as needed.
Fertilization improves bulb performance. Newly planted bulbs will have improved quality and fertilization encourages bulbs to perennialize, or flower for several years without replacing or dividing the bulbs.
There are two fertilizer systems available for spring-flowering bulbs. The first system utilizes a single fall application at planting. You can purchase a sulfur-coated, slow-release complete fertilizer. This should be incorporated into the rooting area at planting time at a rate of one rounded tablespoon per square foot. The second system uses bone meal incorporated in the rooting area at planting time with an application of 8-8-8 (one level tablespoon) or 10-10-10 (one rounded teaspoon) in the fall, followed by a repeat application of the same fertilizer as soon as you see shoots breaking the ground in the spring.
To provide early color and hide the bulb’s foliage after it becomes yellowed and worn after flowering, interplanting is a great solution. Mix bulb plantings among shrubs, perennials, and ground covers to liven up drab areas. Many bulbs will bloom in the spring sun before deciduous trees leaf out. Summer perennials and annuals can mask the ripening foliage of bulbs. To hide dying bulb foliage, plant sun perennials such as rudbeckia, phlox, sedum, daylilies, coreopsis, salvias, Siberian iris, daisies, and verbena; or part-shade perennials such as hosta, hardy begonia, ferns, hellebores, bleeding heart, astilbe, and columbine. Do not cut off or tie the ripening foliage as this will inhibit the production of nutrients for the following blooming season.
An alternative to planting bulbs in the landscape is to grow your bulbs in plastic containers set in the ground of your garden. When spring arrives, remove the pots as the bulbs start to bloom and place them around your porch, patio, or deck. By using early-, mid-, and late-season blooming flowers, you can orchestrate a continuous show for a couple of months. Planting in pots protects the bulbs from the critters that enjoy a feast of tulips, lilies, and crocuses. You do not have to bury your containers; just be sure if you are planting in pots that the bulbs are planted at the correct depth and the pots are large enough to provide winter protection.
The insect most likely to cause a problem with plants grown from bulbs is the aphid. Aphids can be readily controlled by available insecticides. Check labels for recommendations.
We advise against your splitting or harvesting bulbs. If bulbs are performing satisfactorily, do not disturb them. If performance is unsatisfactory, remove the entire plant as soon as the flowers are finished and replant next fall with new bulbs.
Recommendations for the use of chemicals are included in this article as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by North Carolina State University, North Carolina A&T State University, or the North Carolina Cooperative Extension Service nor discrimination against similar products or services not mentioned. Individuals who use chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical. For assistance, contact the North Carolina Cooperative Extension Service.
Send your gardening questions or comments to: Brunswick County Master Gardener Column, P.O. Box 109, Bolivia, NC 28422, or call (910) 253-2610. Enclose a self-addressed stamped envelope if requesting information or a reply. Answers may be printed in this column.
For further information or assistance, please e-mail:
Charlie Spencer,
Brunswick County Extension Master GardenersmVolunteer
Back to the Master Gardenersm News Column Page of the Brunswick County Center of the North Carolina Cooperative Extension Service.
Back to the Home Page of the Brunswick County Center of the North Carolina Cooperative Extension Service.
This site is maintained by Kathy Walters.
URL Address: http://www.ces.ncsu.edu/brunswick/
Date Created 11/30/2005