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Growing camellias in North Carolina: Fighting disease and pests

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By Shirley Waggoner-Eisenman
Brunswick County Master Gardener

Camellias may be propagated from seed (five to six years), by cuttings (three years), by grafting (two to three years), or by air layering (one year).
Camellia blooms will last four to five days when floated in water in a shallow bowl. Blooms treated with gibberellic acid forces the flower to be larger and bloom earlier.
The following varieties are recommended for beginning growers:
Debutante: Light pink, medium bloom in a full peony form.
Alba Plena: White, medium bloom, formal double bloom.
Mathotiana: Crimson, large bloom, rose form to formal double.
R.L. Wheeler: Rose pink, large bloom, semi-double to anemone form.
Nuccio Gem: White, medium to large bloom, formal double.
Magnolia Flora: Light pink, medium bloom, semi-double form.
Many first-time growers usually kill their plants by improper planting. Camellias require three things for vigorous growth: air, water and nutrients.
A raised bed may be used (8-14 inches higher than grade) amended with compost, peat moss or other appropriate organic matter, which should be mixed with native soil.
The raised bed will place the root system above puddled water and this will allow for better aeration of the root system. The organic matter helps hold the water and nutrients in the soil and prevent root rot.
Camellias are not heavy feeders, so the soil should be properly amended so the roots can extract the nutrients needed for healthy growth from the soil.
Inspect your plants frequently for signs of diseases and insects.
Die-back and canker
A fungal disease that forms cankers on twigs and causes branches to die back. Young, succulent shoots suddenly wilt and die, leaves turn dark brown but may remain attached to the shoot for some time. Where the dead and living tissue join, a small area of bark and woody tissue may turn brown.
To control this disease, remove dead twigs or branches well below any visible cankers. Burn all infected debris. Always use clean tools to prevent the transfer of the fungus to new wounds. Dip your cutting tool in alcohol before each new cut.
Flower blight
The disease causing flower blight invades the flower as soon as the tips of the petals are visible. The first signs are small, irregular, brownish specks on the expanding flowers.
In warm, humid weather, the specks enlarge until the entire flower becomes a dull brown and falls off. If allowed to continue, this fungus endures through the winter and spores will infect new flowers the following spring. To control, gather and destroy all fallen flowers for at least two seasons.
New infections can often be prevented by placing a 3-inch mulch of woodchips at the base of each plant. This acts as a barrier to prevent the spores blowing onto the leaves or flowers. A plant damaged by frost may be weakened enough to allow the flower blight to invade.
Leaf gall
Leaf gall is caused by a fungus that invades new leaf tissue in the spring. Infected tissues swell and appear fleshy; a whitish, fleshy gall will appear on the leaf by summer. Prune out and burn these galls and apply appropriate fungicides.
Leaf scorch
Leaf scorch occurs when the leaves dry out during freezing winter weather and the plant cannot get enough moisture. Water plants in winter, mulch heavy, and provide windbreaks. The scorch may also result from too much sun, too much or too little fertilizer, or too deep planting.
Chlorosis
Chlorosis is caused by deficiency of some elements in soil, especially iron; will cause yellow leaves or yellow areas on leaves to appear. Treatment of iron chelate to the foliage or soil or both is usually advised.
Bud drop
Bud drop results from growing in an unfavorable environment. The tips of young buds and edges of petals turn brown and decay or drop off completely.
If your plant is indoors, bud drop is usually from over watering, insufficient light, high temperature or pot-bound roots.
Outdoor plants may drop buds during severe frost or freezing. Bud drop may result from lack of adequate water. Always water when necessary.
Scales
Leaves or bark frequently become encrusted with hard-shelled insects. They feed on plant juices and cause injury or death. The most common of all species are tiny, flat, and yellow. They can sometimes be seen crawling on leaves in the summer. Always treat with the proper insecticides. Characteristics of adult scales are as follow:
Tea scale: Brownish shell, about 1-inch long, yellow blotches on upper leaf surfaces; infested leaves drop off prematurely.
Peony scale: Grayish brown, grows to about 1/10-inch, burrows between the bark of twigs and stems, and feeds on the plant juices. Infested areas swell, later sink; small green stems die quickly. Produces one generation of young per season; other scale species produce several generations each season.
Wax scale: Reddish-brown body with a white, thick or slightly pink waxy coating, about one-third inch long. Causes stunting or dying of plant. When in the crawler stage, spray leaves and twigs with appropriate insecticides three times or more at 10-15-day intervals—begin in May or June; some species can be controlled in the summer months.
Whiteflies
Adult whiteflies are tiny; they have pale yellow bodies and white powdered wings. The young feed on underleaf and cause black, sooty deposits.
Mealybugs
Mealybugs are oval or elongated about one-fifth inch, with a white waxy or mealy covering. Black sooty mold on leaves followed by wilting and dying of the leaves is a sign of their infestation. They are found in clusters along the veins and undersides of leaves or in crotches of twigs. They secrete a sticky honeydew that attracts ants; the ants feed on the honeydew and spread the mealybugs to other plants.
Fuller Rose Beetle
Fuller Rose Beetles leave black excrement on the leaves and eat notches in the leaf margins. This is a common pest in the South. The adult beetle has a brown or grayish body, about 3/8-inch long and a white diagonal stripe across each side.
Mites
The sign of the common red mite is leaves that speckle and turn rusty brown.
The dark red pest is common throughout the South. It will attack both upper and lower leaf surfaces. It lays shiny eggs that look like red peppers.
Feeding injury starts in April and ends in the fall. Injured leaves do not recover, but control measures will prevent injury to new growth.
For more information on camellias, contact your local Cooperative Extension Service.

Send your gardening questions or comments to: Brunswick County Master Gardener Column, P.O. Box 109, Bolivia, NC 28422, or call 253-2610. Enclose a self-addressed stamped envelope if requesting information or a reply. Answers may be printed in this column.