The Aucuba and Wilting

General Care

• Provide optimal care to your aucuba plants to ensure healthy growth and strong plants that are capable of fending off and recovering easily from wilt problems. Grow aucubas in partial to full shade -- in full sun, the leaves will burn and turn black. For best growth, maintain moist, well-draining soil, rich in organic content. Aucubas grow best in U.S. Department of Agriculture plant hardiness zones 7 through 10.

Disease

• Wilted aucuba plants may be the result of a fungal infection called crown rot. Caused by the fungal pathogen Sclerotium rolfsii, which lives in soil, this disease first appears as yellowed, wilted leaves, particularly during humid weather. Crown rot kills the aucuba plant near the soil line, resulting in a black, decaying stem. In addition, white threadlike fungal growths often develop where the stem is rotting. Because fungicides cannot save an already diseased plant, it's best to remove the plant. To prevent infection, always sterilize your garden tools and replace mulch with a fresh batch to protect other garden plants.

Pests

• If your aucuba plant is covered with bumps and its leaves are wilting, you are likely witnessing a scale insect infestation. These typically immobile pests find a feeding spot on plant surfaces and remain there indefinitely. Scales are sucking pests that feed on plant sap. Their humped bodies often look like natural extensions, or bumps, on plants. As they feed, damage may include yellowed, wilted, curled leaves and leaf drop. Control this problem by removing and destroying heavily affected branches. Release natural enemies, such as parasitic wasps and twicestabbed lady beetles, as a natural means of management. For severe infestations, apply horticultural oil to control pests. Follow the instructions on the the product label, which may direct you to mix 5 tablespoons of oil per 1 gallon of water. Apply with a sprayer, reapplying only once monthly. Don't use this product if the temperature is above 90 degrees Fahrenheit.

Cultural Problems

• A wilting aucuba may simply be a maintenance or care problem. Aucubas require regular watering. The Soil should be neither dry nor wet. If you consistently over-water your aucuba or if heavy, consistent rains result in wet soil, your plant may drown. When left in standing water, the roots suffocate and the plant will slowly decay as leaves wilt and discolor. If you don't water enough, the leaves will wilt, lose color and fall to the ground. Prevent wet soil by improving drainage. Incorporate organic content, such as compost, into the upper layers of soil to improve drainage. Wait until the top layer of soil feels dry to the touch before watering an aucuba. Check daily to avoid allowing the soil to dry out completely.