As I mentioned before, we are nearing the end of any soil applications of iron fertilizers that work. You can still do it now but don’t expect glorious results like you would see when you apply it at the beginning of new growth (spring).  Soil applied iron applications will end about April-May as new growth slows down and finishes. These iron fertilizers and include Kerex, EDDHA iron chelates and any other iron fertilizers meant to be applied to the soil.  Kerex iron application was made to the soil near this plum in April of 2015. Didnt work. Should have used EDDHA iron chelate or more of the Kerex or added compost AND then applied Kerex. If there is not enough soil “organics” to decompose then any iron fertilizer will work. Decomposition of organics in the soil lowers its alkalinity and makes just about any iron fertilizer work. Bottom line, be careful greening up plants that have been growing in rock mulch more than three or four years. Once early spring through early summer has passed, the only thing that cures leaf yellowing are the leaf sprays applied directly to yellowing leaves.  This chelate is iron EDTA, not EDDHA. EDTA chelated iron works well IF the soil alkalinity (pH) is 7.6 or below. For any iron to work well also requires that nitrogen fertilizer is present. Always apply iron chelates with a well fertilized plant OR include a nitrogen fertilizer at the same time. Iron sprays like this one are less expensive but you MUST adjust the water chemistry either by adding  a cup of vinegar (acetic acid) to a gallon of water or use distilled/deionized water. That’s a poor substitute for soil applications of iron, best done earlier in the season (late January- March) but sometimes the yellowing is so severe it must be done when it’s seen. Sometimes the yellowing of plants is so severe that an iron application, either applied to the soil or sprayed on the leaves (or both), is necessary to prevent death or injury to the plant.             Just remember the alkalinity of our tap water is very, very important to a spray’s effectiveness so either adjust the alkalinity of tap water with a cup of vinegar for each gallon or use distilled water for your iron spray.             Regarding applications of fertilizer, do the trees really need it? It’s best to apply plant growth fertilizers in the spring but applying it now, if desperate, is still better than nothing. Applying fertilizers when trees don’t need it is a waste of fertilizer, a waste of money and unhealthy for the trees. New growth in apricot. Excessive. Should be an average of about 18 inches.  Look in several locations at the color of the leaves and the amount of new growth. If the leaves are a very dark green and new growth is exploding, your trees don’t need a fertilizer application. Save the fertilizer application for next February or, least wise, the November coming up. Dense canopy of a fruit tree. Add no fertilizer this year.

 Iron applications are applied to the soil earlier in the year and sprayed on leaves later in the year. Learn why and how on this episode of Desert Horticulture. Interveinal chlorosis (yellowing) on apricot growing on a desert soil.