Aucuba japonica is commonly referred to as Japanese aucuba or gold-dust tree. It is a broadleaf evergreen shrub that grows slowly. It grows in United States Department of Agriculture's (USDA) hardiness zones 6 to 10. It is native to Japan, but is grown in gardens in Europe and the U.S.
The aucuba is a slower growing evergreen but good watering and fertilizing can speed up the growth rate. Eventually, it will reach heights of 6 to 10 feet tall with a width of 4 to 5 feet. It has many stems with multiple shiny, leathery leaves. Some varieties have variegated or yellow-spotted leaves. Aucuba plants are either female or male. The male plants have small purple flowers and the female plants produce red berries.
Aucuba plants are easy to grow and are drought- and pollution-tolerant. They prefer shade to deep shade locations, otherwise the leaves will burn in the sun.They prefer moist, well-drained soil that's rich in organic matter. Overhead watering can promote disease, so water from the bottom. Prune in spring before new growth begins. Pruning aucubas can be to create dense screens in the landscape or to control growth size. They need light fertilizing in the spring.
Aucuba works well in dark corners of the yard. The variegated leaves can brighten or break up the dullness of dark areas when planted in groupings. With each plant being a separate sex, plant several females with one male nearby.
Aucuba is also a good container plant, in entry areas, as foundation plantings or under canopies of large trees. Acubuas can compete with the roots of other trees and shrubs for water and nutrients.
Diseases and Pests
Aucubas suffer from several diseases and pest problems. Most of these problems have to do with the roots. Crown rot is caused by the fungus Sclerotium. The fungus attacks plants at ground level in humid conditions. Black decay develops and moves up the stem. The leaves wilt and the plant dies. Leaf problems can develop, but usually as a result of the root problems infecting the plant.
Root rot is caused by a soil-borne fungi Phytophthora cinnamomi and P. citricola. The leaves wilt the same as with crown rot but the roots rot more extensively. Infected plants with root rot will die too.
Nematodes or small round worms cause the most root damage in aucuabas. They produce galls on the roots which reduce vigor and growth by interfering with plants taking up water and nutrients.
Control should start with prevention. Inspect plants for healthy roots and stems. Don't plant new plants where old plants have died previously. Aucubas should not be planted too deep. Fertilize lightly and mulch, but not too close to the main stem.