Best Iron to Use is EDDHA Chelated Iron

Q. I’m starting to think about the springtime approaching and the need for fertilizing. Do you have an “iron Fertilizer” you recommend? We added the compost you suggested but I want to make sure we are on top of the iron needs of our plants.

Iron chelate fertilizer that works in all soils. Its a bit more expensive but it is a guarantee. The others will work most of the time.

A. The iron chelate I like to use is a little bit more expensive. The reason I recommend it is because of its stability in both highly alkaline and highly acidic soils. It works regardless of the soil or its alkalinity (soil pH). I consider it cheap insurance.

Severe iron chlorosis on a peach seedling. Chlorosis is any yellowing leaving behind green veins. Iron chlorosis occurs all summer long but it is on new growth. Iron should be applied sometime in the early or mid spring, before April in our climate.

The chelate I like to use is EDDHA iron chelate. It comes under several names but as long as the iron is bound to the EDDHA chelate then it is what I recommend. Other types of chelates and iron fertilizers stop working in highly alkaline soils.

This is another iron chelate fertilizer called EDTA. It works in most soils. It is the most common form of chelated iron fertilizers for plants because its more available and cheaper.

            If you are adding compost to compost amended soil then any chelate or iron fertilizer will probably work whether it is iron sulfate, brake filings, or iron chelates such as EDTA or DTPA This is because soils that have compost added to them usually are not strongly alkaline. The compost additions, along with water, usually lowers the alkalinity of the soil.

The chelated iron I prefer, iron EDDHA, works over all of the different soil pH or alkalinity.

            Any iron fertilizer or chelate MUST be applied and mixed with the soil in the early spring (sometime soon after February 1 in our Las Vegas climate). Soil applications get less effective as the growth begins stopping. By mid to late summer you must switch to iron fertilizers applied as a liquid to the leaves for acceptable results. This usually requires several applications to shrub leaves. Iron fertilizers applied wet to the leaves (foliar applications of iron) are not as effective and may need to be applied to the leaves of trees and shrubs several times to work.