Palms (Palmaceae)

Palms (Palmaceae)

Plant Health Problems

Diseases caused by Physiological/Environmental Factors:

Leaf spot or Tip burn, physiological.
Tips of leaves or fronds develop brown, necrotic areas. This problem can be associated with a number of factors including root damage from overfertilization and low relative humidity.

Symptoms can be minimized by careful attention and review of cultural practices. The appearance of the plant can be improved when affected portions are removed with clean, sharp scissors.

Insect Problems:

Picture of Mexican Mealybug
Mealybugs. Phenacoccus citri, P. gossypii, P. longispinus
Palms and other plants in greenhouses and homes are commonly infested with mealybugs. White cottony masses appear on leaf surfaces, in leaf axils and sheaths. These insects damage plants by sucking plant sap. Sprays of insecticidal soap, ultra-fine horticultural oil or resmethrin, which are among the compounds registered for control of this pest in Connecticut, are most effective against crawlers. Because of overlapping life stages in a home environment, multiple applications will be needed to control this pest. The spray needs to contact the insect so direct it downward into growing tips and leaf axils. Root mealybugs specialize as root feeders, and the only aboveground sign of infestation is loss of vigor in infested plants. Foliar-feeding and root mealybugs can be controlled with imidacloprid applied as a systemic to be taken up by the roots. Read and follow all label directions for any insecticide used. For egg-laying mealybugs, such as P. citri, releases of the mealybug destroyer ladybeetle may be useful.

Scale insects.
Many kinds of scale insects infest the different species and varieties of palms in greenhouses and dwellings. Some of the more important species are as follows: hemispherical scale, soft scale, circular scale, Morgan's scale, and thread scale. Among the compounds registered for control of this pest in Connecticut are horticultural oil, insecticidal soap and imidacloprid. Except for coconut palms, palms can be sprayed with ultrafine horticultural oil to suffocate scales. Otherwise, repeated application of insecticidal soap may be necessary to control crawlers. Imidacloprid is only useful as a systemic treatment for honeydew-producing species of scales. Consult the labels for dosage rates and safety precautions.