What Are the Brown Leaves on Potted Palm Trees?

Diamond Scale

• Diamond scale is a foliage fungal disease of palms caused by the fungus Phaeochoropsis neowashingtoniae and leads to browning and yellowing leaves. Early symptoms includes the appearance of small, water soaked spots on upper and lower foliage, petioles and stalks. The older or lower foliage is most susceptible to the disease. As disease progresses, it leads to the death of entire infected leaf, thinning the plant crown. Management includes keeping palms in good health and avoiding keeping soil excessively wet. There are no fungicides recommended for diamond scale.

Fusarium Wilt

• Fusarium wilt is a potentially fatal disease of all palms, including potted palms, caused by the fungus Fusarium oxysporium. The disease starts in the older or lower foliage and moves to the center and new leaves causing yellowing or browning of foliage. The brown leaves do not fall off the plant but remain hanging. Fusarium wilt is also indicated by a heavy, black to brown discoloration along the petioles. Infected palms can die within a few months or linger for years after infection. Fusarium wilt is a 100 percent fatal disease and there are no chemical control options. Management includes buying tree for good sources and avoiding keep soil excessively moist.

Mineral Deficiencies

• Mineral deficiencies in palms are a common reason for yellowing and browning foliage. In cases of severe deficiencies, entire tree growth is stunted and there is gradual dieback. Minerals commonly lacking include nitrogen, magnesium or potassium. Often the deficiency occurs not because the soil itself is lacking in these minerals but due to some other conditions that reduce the plant's capacity to absorb them. For example, the excess of one nutrient can retard the uptake of other important nutrients. Management includes adequate cultural care such as a well drained soil and using specially formulated palm fertilizers.