The long-term solution to this problem is to lower soil pH according to the section on soil acidification, preferably before planting. A short-term solution is to apply a foliar iron chelate to the leaves or soil. Chelate is a chemical compound that keeps the iron available over a wide pH range. Various chelate products are available at garden stores. Follow label directions for appropriate rates to apply.
Foliar applications have to be repeated several times during the growing season.
Soil applications need to be made on a yearly basis. However, higher rates are needed compared to foliar applications, leading to increased cost. The chlorotic tree can also be injected with iron chelates. This technique can correct the problem for a few years, but repeated injections may be necessary, leading to some damage of the tree trunk.