What Is Wrong With My Coffee Plant?

Are the seedlings dying and the stems are girdled or rotted at the soil line?

Are there any angular or circular green to gray spots with brown borders on leaves?

Are there any small, circular red lesions with a distinct margin develop on leaves and stems, lesions may enlarge during humid weather conditions?

Are the leaves pale on their upper side and are there any dusty blisters on the undersides?

Are the leaves distorted and yellow?

Are there any green oval-shaped bumps concentrated on leaf veins and tips of new shoots?

Are the leaves yellow, stems die back?

Do the leaves have tan or brown blotches or serpentine tunnels?

If your seedlings are falling over and the stems are girdled or rotted at the soil line, the most likely cause is a damping-off disease. Remove and destroy all infected plants. To prevent damping-off let the soil surface dry between waterings, thin seedlings to avoid overcrowding, and do not add nitrogen fertilizers until plants have developed leaves.

These symptoms indicate a fungal disease - Cercospora leaf spot. This fungal disease only occurs in very warm climates. Spots develop a “frog-eye” appearance with light centers and dark edges. Spray plants with copper as soon as symptoms appear to prevent further symptom development.

These symptoms indicate a fungal disease - Anthracnose. Disease emergence is favored by wet conditions. The fungus is spread by splashing water. Keep plants dry when watering to prevent spread. Spray plants with copper when the first pods develop if you have had problems in the past.

Likely cause for these symptoms is a fungal disease - Rust. Provide good air circulation around plants by thining them. Avoid making leaves wet when watering. All infected leaves should be removed. Spray leaves with sulfur early in the season to prevent rust or to treat mild infections.

Distorted, yellow leaves are caused by aphids. These tiny insects cluster under leaves and on growing tips where they feed on plant sap. Leaves, stems, and buds get distorted, and later leaves and flowers drop from the plant. You can control them by washing them off the plant with water spray. Insecticidal soap should be used with severe infestations.

Green coffee scale (Coccus viridis) is a common and serious problem. Scales suck the plant sap resulting in reduced growth and crop yield. Scrape off minor infestations with your fingernail. Prune out badly infested growth, or use a soft brush and soapy water to gently scrub the scales off the stems. Control scales by spraying insecticidal oil during the growing season.

Stem borers are small caterpillars that cause stems and branches to die back. As spring growth begins, you can easily spot borer-infested plants because the leaves look weak and sickly. Affected branches are easily broken off. When trees are first infested there may be evidence of frass (sawdust-like residues) on the ground. The easiest control is to cut out and destroy infested plants as soon as you notice them.

These symptoms are caused by insects - Leafminers. These tiny pale green fly larvae feed between the upper and lower surfaces of the leaves. Prune off and destroy all infested leaves. Remove debris in fall because it might contain overwintering leafminers. The weekly application of insecticidal soap should keep their numbers low. Also, introducing parasitic wasps is a very effective method of controlling leafminers.

If there are white, cottony clusters on leaves and stems the culprits are mealybugs. These tiny insects are covered with a fluffy white coating. You can control them by washing them off the plant with water spray. Insecticidal soap should be used with severe infestations.