|My two potted palms are becoming very yellow and was wondering what they are lacking. They get fertilized and watered.|
|Yellow leaves can be caused by many things including lack of nitrogen, insufficient light, water-logged soil (plant roots need oxygen to thrive), dry soil, or iron deficiency. If the older bottom leaves are yellow, but new growth is green, it's usually a lack of nitrogen. If new leaves are yellow, with green veins, it's usually a lack of iron. Soil should be kept moderately moist (but not wet). Finally, transplant shock can contribute to yellowing. If new growth shows up as green, that might be the problem. Try to isolate each of these possibilities one at a time to determine the problem.
Also, palm trees are susceptible to nitrogen, potassium, and magnesium nutrient deficiencies, and they also need various micronutrients. I recommend you use a fertilizer formulated especially for palms. According to University of Arizona experts, it should have 10-20% Nitrogen and Phosphorus, 5% Potassium and 1-3% Mg, .5% Mn, .5% Fe, as well as trace amounts of S, Zn, Cu and B. This will be on the package label. Follow instructions exactly for amounts and water well after application. Good luck with your palms.