Transplanting from the woods is not recommended: You must duplicate the growing environment of the woods if the tree is to survive, and even when these conditions are met, the survival rate is low. Further, you may be transporting insects and diseases into an area where they did not previously occur. If you still desire to do this, however, you should select a very small tree. Root prune the tree in spring and move it the following fall. Have the new planting site prepared before digging the tree. Survival will depend on how many shallow feeder roots you move, not the amount of soil. Dig on a cool day and keep roots moist at all times. Put a dot of paint on the north side of the tree before digging, and replant with that dot facing north in the new site.
Site: Light shade, 1/2 day of sun or filtered shade. Dogwoods are understory trees and need the shade of a canopy to protect them from the hot summer sun. Good drainage is crucial. Do a "perk test" for drainage before planting. Dig a hole 12" deep and fill it with water. Check in 6 hours. If the hole doesn't drain within 5-6 hours, you should "plant high." Flowering will be decreased by deep shade or if crowded by other trees which compete for water and nutrients. Recent research reports show that dogwoods growing in well-drained areas and receiving 1/2 day of sunshine are at significantly lower risk for fungal infections.
Planting: Dogwoods grow best in well-drained, acid soil, with a pH near 5.5, and a soil mixture containing generous amounts of organic matter. See page 4 for diagram and planting instructions.
Fertilizer: Dogwoods prefer being fed by the slowly decomposing mulch rather than by chemical fertilizers. If you do fertilize, do it sparingly in April/May when the leaves are coming out. Dogwoods in natural areas usually do not require fertilization. Recent research suggests that root growth is promoted by using little or no Nitrogen fertilizer the first year after transplanting.
Watering: Since they are shallow-rooted trees, dogwoods are among the first plants to show drought stress. They need supplemental water in the absence of regular rainfall, especially during the summer and fall. Water in the morning, preferably with a soaker hose, to a depth of 6". Use of a sprinkler is not recommended because it wets the foliage, setting up ideal conditions for certain diseases.
Pruning: Prune as little as possible, letting the tree assume its natural tree shape, except for cleaning out of dead or broken limbs. If necessary to thin out some branches to permit light penetration and air circulation, do this during the dormant season. Avoid cutting dogwoods during summer months when the Dogwood Borer is active; if unavoidable, spray cuts with Lindane. Leaving lower branches on the tree helps shade the shallow root system, but do not allow any branches to touch the ground.
Trees not flowering: The most common causes are:
Deterioration of dogwoods: Cultural factors which may cause deterioration of dogwoods are:
Vertical cracking of bark: can be caused by 1) lawn mower/weed-eater injury, and 2) weather. Trees often have thin bark from close planting in the nursery. When taken home and planted in full sun, the thin bark splits readily. Do not cover wounds with tree paints. Provide good growing conditions so that the plant can heal itself.
Weed Control: is best accomplished by using mulch. Use lawn herbicides with caution. The shallow roots of dogwood can pick up herbicides with high leaching potential, such as dicamba.
Spot Anthracnose, Septoria Leafspot, and Ascochyta Blight appear almost every year. They do not usually cause permanent damage to established trees. However, severe recurrences year after year may weaken trees, making them more susceptible to diseases, and flower production may be reduced. All three diseases can occur on the same leaf at the same time. The best disease control is observing good cultural practices to keep the tree healthy.
Spot Anthracnose (Elsinoe Corni): Is not likely to kill the tree. This native fungus has been around a long time; it is common in wet, rainy, cool springs. The foliage looks terrible but there is usually enough green on the leaves for survival of the tree. Small red dots on petals appear early in spring. Flowers do not open normally. Purplish circular or angular spots appear on foliage, and centers may turn pale yellow-gray and drop out; leaves wrinkle and some may fall. The fungus overwinters on twigs and fruits, infecting the opening flowers the following spring. Treatment with fungicide is possible but some homeowners may not find it practicable to spray every 10-14 days from bud break until midsummer. Maintain the good health of the tree by observing the four essentials for growing dogwoods in Cumberland County.
Anthracnose(Discula sp.) This is the fungus disease you have read about in the newspapers that is killing dogwoods in natural areas, spreading from the northeast through the Applachians. As of the spring of 1995, the disease has not attacked home gardens locally. The fungus needs cool, wet conditions and has difficulty surviving hot summer temperatures. All cultivars of the common dogwood (Cornus florida) are susceptible. Cornus kousa, the Chinese dogwood, is resistant. Clearly it would be foolhardy to transplant any trees from the mountain areas into your home garden.
The disease starts early in the season (at that time it is hard to distinguish from Spot Anthracnose), often at the tip of the leaf. The leaf blight increases as the season progresses until the leaves finally die. Anthracnose (Discula) differs from Spot Anthracnose in that the spots on the leaves enlarge until the leaf dies but the dead leaves stay on the tree. Once the infection occurs, there is no "cure."
Septoria Leafspot: Usually does not become severe until mid- to late summer, but are most likely to be a problem when wet conditions persist and humidity is high. Symptoms include medium uniform, purplish spots or lesions on the leaves; the centers often become grayish as the season progresses. Septoria also causes the fruit to have a rough, black surface.
Ascochyta Blight: A foliar disease that usually appears in June after a wet spring. The round-to- irregular spots are characterized by a gray-to-tan center with a dark border and may be as large as 1/4" in diameter. The entire leaf may collapse, shrivel, and turn black.
Root Rot and Crown Rot diseases are caused by fungi usually present in the soil which attack when the tree is under stress from injury or unfavorable soil conditions. The first symptom is dying of the leaf margin on the leaves, followed by general decline and eventual death of the tree. Prevent root rot diseases by planting only in well-drained soils and maintaining the vigor of the tree with proper cultural practices. Once an infection occurs, there is no "cure."
Crown Canker: Develops on lower trunk near ground line. The fungus kills the bark just above the ground level. Often infected areas will ooze a dark colored fluid. Over time, the killed area of the bark becomes sunken, dries, and falls away, leaving the wood exposed. The injured area makes an easy entry place for borers. The best control is prevention. Avoid injuries and maintain vigor of tree. Once the crown canker fungus has invaded a large part of the trunk base, it is too late for control measures.
DISEASE CONTROL: Good cultural practices and sanitation are helpful in controlling diseases. Rake up and destroy any diseased leaves or twigs, since they harbor the innoculum for next year. Other control measures include: 1) thinning branches to increase air movement through the tree, 2) removal or limbing of adjacent trees which impede air flow, and 3) avoiding overfertilization and the resultant production of excess foliage. If additional measures are required, the following program should be effective, using any one of the following materials: Captan 50% wettable powder (read label directions carefully for amounts to use); Maneb 80% wettable powder; Zineb 75% wettable powder; and Chlorothalonil (Daconil 2787).
Timing of sprays:
Dogwood Borer: A serious threat to dogwoods in Cumberland County. The borer is most active in June/early July. If not controlled, borer damage will definitely shorten the life of the tree. Control: spray trunk and lower limbs with endosulfan (Thiodan) or Lindane early in June and repeat the spray at least 2 times at 10-day intervals. Avoid cutting dogwood during summer months.
Cottony Maple Leaf Scale: Undersides of leaves, stems, or branch crotches are covered with white, cottony masses. Leaves may yellow and drop prematurely. Black sooty mold often grows on honeydew. Control as needed in midsummer with Diazinon, Sevin or Malathion sprays according to label directions. The following spring, when trees are dormant, spray with Lime Sulfur to control insects on the bark.
Dogwood Club-Gall Midge: Club-shaped galls or spindle-shaped swellings on twigs of dogwood, caused by a reddish-brown midge. Damage usually appears as withering leaves on branch tips during the growing season. Small orange larvae develop in the galls until early fall, when they drop to the ground. Control by pruning out dead and infected twigs and branches and disposing of them properly.
Seedcorn Maggot, Adults: The adults look like small black flies. These insects do not damage the tree. No control is necessary.
After selecting a suitable location, mark out a planting area at least five times the diameter of the planting ball. Use a rototiller or shovel to loosen and break up the soil in this entire area no deeper than the depth of the root ball.
Backfill mixture: Use 1/3 (no more) pine bark mulch or mini-chips/nuggets with 2/3 original soil, and mix thoroughly throughout the entire potential root area. If tree is balled and burlapped, no soil amendment is necessary, but the soil in the entire root area must be broken up. You may mix 1/2 cup of superphosphate into the backfill mix, but do not use any other fertilizer at planting time. Bringing in new topsoil is not recommended since ultimately the tree must grow in our native soil.
Planting: Clear a shallow saucer in the center of the loosened soil area, locating the bottom of the root ball on original soil, as shown. Dogwoods are shallow-rooted plants, so avoid planting them too deep. If you have very good drainage, set the tree at same depth it grew in the nursery. If drainage is poor, plant high. Container-grown plants may be rootbound; loosen and spread roots around in the saucer. If balled and burlapped, open burlap to speed soil-root contact.
Backfill around the root area and gently pack the soil to prevent major air pockets, but it is a mistake to pack the soil too hard. Water should be used instead of your foot to help the soil settle and prevent overpacking. Rake soil even over the entire planting area.
Mulch: Cover the soil with 2-4" of mulch, preferably pine bark mulch or chips, or pine needles. Maintaining a constant protective layer of mulch will improve tree growth substantially, conserve moisture, discourage weeds, insulate roots from cold and heat, and protect the trunk from lawn mower and weed-eater injuries, which provide entry points for insects and diseases.
Water: Shallow-rooted trees react readily to lack of moisture. Pay close attention to watering for the first year until the tree is well established.
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