Leaf color quickly dark-ens in response to either soil or foliar fertilization. Potassium deficiency is perhaps the most widespread and serious of all disorders in Florida palms. Symptoms occur first on oldest leaves and affects progressively newer leaves as the deficiency becomes more severe. These may or may not be accompanied by necrotic spots. It is also the leaflet tips, rather than the margins, that become necrotic as the deficiency progresses.
Potassium is translocated from older to new leaves as required by the palm.
In severe deficiencies, the canopy will be greatly reduced in size due to the removal of K from all leaves. Without prompt treatment, the palms will usually die. K deficiency affects all species of palms, but is most severe in royal, queen, coconut, areca, and spindle palms. Symptomatic leaves on K-deficient palms will never recover and must be replaced by new, healthy leaves. In severely deficient palms, this means replacing the entire canopy which may take 2 years or longer.