Palm Disease Guide: Nutritional, Environmental, and Fungal Disorders

Managing Diseases and Disorders in Ornamental Palms

Ornamental palms face a unique combination of nutritional disorders, environmental injuries, and fungal diseases. Proper diagnosis requires distinguishing between biotic and abiotic causes, as symptoms often overlap. This guide covers the most common issues in palm production and maintenance.

Cold Injury

Reddish dead leaf areas within 5 days of exposure to temperatures below 40°F.

Management: Don't place near air conditioners. Maintain temperatures above 45°F.

Fluoride Injury

Chamaedorea: leaf tips turn dark brown and die. Areca: small dead spots in chains between veins. Caused by excessive soil fluoride.

Management: Maintain soil pH 6.0-6.5. Avoid perlite and superphosphate. Don't irrigate with water containing 1 ppm fluoride.

Helminthosporium Leaf Spot

Drechslera setariae, Exserohilum rostratum, Phaeotrichoconis crotalariae cause reddish-brown to black oval spots (<1/4 inch) merging into irregular shapes.

Management: Avoid overhead watering. Apply protective fungicides.

Iron or Copper Toxicity

Oval dead leaf spots with yellow halos, confusable with Helminthosporium leaf spot. Caused by excessive iron fertilization or copper fungicide use.

Management: Don't use copper fungicides. Don't use iron sequestrene under low light, high nutrient conditions.

Leaf Burn

Lower leaf tips brown and die from excessive fertilization.

Management: Maintain moderate fertilizer levels.

Additional Resources

For detailed information, see Compendium of Ornamental Palm Diseases and Disorders (2004), edited by M.L. Elliott, T.K. Broschat, J.Y. Uchida, and G.W. Simone. APS Press, 69 pp. with color photos. Available at 1-800-328-7560. A CD of palm diseases and disorders is also available.

Integrated Palm Health Management

Successful palm management requires: distinguishing biotic vs. abiotic causes (critical for proper treatment); maintaining optimal soil pH (6.0-6.5) for nutrient availability and fluoride management; avoiding overhead irrigation; moderate, balanced fertilization; cold protection; and targeted fungicide use only for confirmed fungal diseases. Many palm "diseases" are actually nutritional or environmental disorders requiring cultural correction rather than pesticide application.