Iron deficiency in palm trees is primarily a cosmetic problem. Palm trees usually survive, but will exhibit green veins surrounded by yellow tissue, and this is usually seen on newest leaves first.
As the iron deficiency becomes more severe, new leaves will show extensive tip necrosis, and there will be a reduction in leaf size. Iron deficiency in palm trees is usually induced in palms growing on poorly aerated soils (compacted or over-watered) or in palms planted too deeply. Iron deficiency may occur in palms with a damaged or inadequate root system which leaves the plant unable to take up sufficient nutrients from the soil. This deficiency is much less often caused by a lack of iron in the soil, or by high pH soils.
Prevention and Treatment of Iron Deficiency
In alkaline soils, iron-deficient palms can be treated with chelated iron fertilizers. In some cases, iron deficiency symptoms can be temporarily alleviated by regular foliar applications of chelated iron or iron sulfate, but long term corrections will only occur when the poor soil aeration or proper planting depth is corrected. The rate of iron sulfate to use for foliar application is ½ teaspoon per gallon of water. Spray the foliage to runoff.