Foliage Damaged In Winter due to Wind Chill
Severe wind chill may damage the foliage during the winter but euonymus shrubs usually regenerate themselves every spring. Some variegated forms may revert to green if they experience a severe wind chill. This problem can be controlled somewhat by surrounding shrubs with protective material such as burlap or agricultural fleece. If wind is an annual problem, move the plant to a more protected location on the north or east sides of the house.
Leaves and Stems Covered With Small Bumps means Scale Insects
Scale insects form groups of small bumps or blister-like outgrowths on stems and leaves. These are waxy shells that protect the insect beneath as it feeds. The shells may be white, yellow or brown to black, and are about 1/25 to 1/50 inch in diameter. Scale is the nemesis of evergreen euonymus and other members of the euonymus family. The first sign of a scale attack is often discoloration of upper leaf surfaces, followed by leaf drop, reduced growth, and stunted plants. Heavy infestations kill winter creepers. Some scale species secrete honeydew, which coats foliage and encourages ants and sooty molds. Scale outbreaks can be triggered by pesticides used against other pests or by environmental stresses such as too much or too little water. Over fertilizing may encourage lush growth susceptible to scale attack.
Scrape minor scale infestations off plant surfaces with a fingernail, or use a cotton swab dipped in rubbing alcohol. Spray heavily infested plants with a mixture of alcohol and insecticidal soap every 3 days for 2 weeks. Add 1 tablespoon of alcohol to a pint of ready to use commercial insecticidal soap spray. To prevent scale, spray dormant plants with a "superior" type oil in late winter or early spring. Apply insecticides when the young larvae (or "crawlers") have hatched and before they start forming their new scales.
For more information see file on Controlling Scale.
Foliage Curls, Turns Yellow indicates Aphids
Aphids are soft-bodied, pear-shaped, green, brown, black, or pinkish insects a little bigger than the head of a pin. They cluster on tender new growth and suck sap from leaves and stems, causing foliage to curl, pucker, and yellow, and reducing the plant's vigor. Ants, attracted by the aphids' honeydew secretions, wander over the plants and protect the pests from natural enemies. Check leaf undersides for small groups of aphids. For light infestations, spray the undersides of the euonymus leaves vigorously with water three times, once every other day, in the early morning. In cases of heavy infestation spray visible aphids with insecticidal soap every 2 to 3 days. As a last resort, spray them with pyrethrum spray.
For more information see file on Controlling Aphids.
Leaves Discolored due to Thrips
Adult thrips are tiny, slender insects, 1/25 inch long, variously colored pale yellowish, black or brown. They rasp leaves and petals, sucking sap from the injury. Leaf surfaces become flecked and whitened and the tips wither, curl up and die. Leaf undersides are spotted with tiny black specks of excrement. Since thrips quickly burrow out of sight deep between petals, early identification and control is essential. Set out yellow sticky traps about 4 weeks after last frost as early warning devices. As soon as you spot thrips on the trap, spray insecticidal soap on nearby euonymus every three days for two weeks.
For more information see file on Dealing with Thrips.
Tumor-like Swellings on Roots, Trunk or Branches. Means Crown Gall
A bacterium sometimes infects euonymus shrubs through wounds and stimulates cells to form tumor-like swellings (galls) with irregular rough surfaces. To avoid crown gall, avoid planting euonymus plants that have galls on the roots or stems. Destroy heavily infected plants. If only a few galls are present, cut off and destroy the affected stems. Sterilize pruning tools afterward in 70% denatured alcohol to avoid spreading the disease.
Sunken Spots On Leaves indicates Anthracnose
This fungal disease forms distinct lesions on euonymus leaves, which appear as moist, sunken spots with fruiting bodies in the center. Leaf spots may run together, resembling a blotch or blight. The dead areas follow the veins or are bounded by larger veins. Sometimes the tips of branches die back to several inches below the buds. Pustules containing pinkish spores appear. Dieback and defoliation may occur in severe cases. Gather and destroy infected fallen leaves. Prune away diseased branches. Maintain plant vigor by feeding and watering well, especially during droughts. Spray with a copper fungicide such as Bordeaux mixture.
For more information see file on Controlling Fungal Disease.
Leaves Spotted, Turn Brown, Drop Prematurely due to Leaf Spot
Leaf spot diseases caused by various fungi occasionally attack euonymus, causing yellow, brown or black dead blotches on their leaves. Often these spots come together to form larger patches of dead tissue. Gathering and destroying fallen leaves usually controls this disease. If needed, spray the vine with a copper fungicide.
For more information see file on Controlling Fungal Disease.
Leaves Covered With White Powder means Powdery Mildew
Powdery mildew caused by fungi sometimes attacks euonymus, especially in the southern states and the Pacific coast. Spray affected shrubs thoroughly with wettable sulfur once or twice at weekly intervals starting as soon as you see the whitish fungus coating the leaves. Collect and discard all above ground refuse in the fall.
For more information see file on Controlling Fungal Disease.
Foliage Burned indicates Dogs.
Dog urine may discolor euonymus foliage and even kill branches. Spraying foliage with an anti transpirant gives some protection. Screen the plants or spray them with an aerosol pet repellant. For more information see the file on Dogs and Cats
