Problems With Potted Eugenia

Scale Insects

• Container-grown Eugenia indoors or out can be targets for sucking, piercing insects called scale. The adults may be found on leaves and stems, where they suck out plant juices, weakening the plant and causing yellowing, wilting leaves. Scale insects leave behind a sticky substance called honeydew that attracts ants and provides a growing medium for sooty mold. Use a magnifying glass to look for small, dome-shaped, cottony-looking shells on the stems and leaves. Use a toothbrush or cotton swab dipped in isopropyl alcohol to scrub the insects off of the plant. If that is not practical, apply a horticultural oil, insecticidal soap or pyrethrin-based chemical insecticide to kill the scale. Follow manufacturer's instructions for proper use.

Spider Mites

• Spider mites, members of the arachnid family, can also infest Eugenia plants, both indoors and out. These mites are tiny, sap-sucking pests that spin equally tiny webs among the plant's foliage and twigs. The easiest way to determine if mites are on your plant is to hold a sheet of paper under a branch and tap the branch sharply. If minute black or red dots cascade onto the paper, you have spider mites. Mites also produce honeydew. Place smaller potted Eugenias in the bathtub or kitchen sink and give them a good, hard shower of water to knock the mites off. Larger container plants can be sprayed off with the garden hose. Repeat every few days for two to three weeks. If the mites persist, use a commercial miticide and follow the label instructions for proper application.

Eugenia Psyllids

• Pruning Eugenia into attractive topiary shapes is one of the plant's strengths but can also lead to one of the plant's weaknesses -- susceptibility to a psyllid attack. Psyllids are mainly a problem in California, where they cause severe damage to Eugenia foliage. A parasitic wasp, Tamarixia, was released by government officials to control Eugenia psyllids. Because the wasp is killed by chemical controls, only cultural control is recommended in California, according to the University of California at Davis Integrated Pest Management program. Maintain plant health with proper watering and fertilizing. Watch for yellowing or crispy leaves following pruning. Outside of California, spray with insecticidal soap every three to four days until the insects are gone. Use a dormant oil on outdoor Eugenia in early spring to help prevent psyillid attacks. Lady beetles and lacewings are natural predators that can also help control psyllids.

Mildews and Fungal Infections

• Eugenia may contract powdery mildew, a fungal infection that makes the plant looks as if it's been dusted with baby powder. Other fungal infections can reach the plant through pruning cuts or may be wind-borne. Keep the plant as healthy as possible to help it resist infections and diseases. Do not over-water or over-fertilize the plant. Fungal infections may appear as watery-looking spots or blotches on the foliage or stems. Prune away infected portions of the plant and apply a fungicide made to treat the specific fungus. Take a sample of the infected portion for positive diagnosis and apply fungicides according to label directions. If the disease is severe, you may need to discard the plant and start over.