By definition, chlorosis is a complete yellowing of the leaf due to lower than normal amounts of Chlorophyll. When the veins are green and the area between the veins are yellow, this is properly termed interveinal chlorosis.
Interveinal chlorosis, often called iron chlorosis can be caused by a deficiency of several micro-nutrients; Iron, Zinc, and Manganese, all of which the symptoms look similar. Yellowing of the leaves can be caused by a number of cultural or environmental issues. Normally it’s due to the pH of the soil being too high.
We have two ways to help correct this yellowing, application through the leaf or application through the soil.
For foliar application we use FL Chelated Liquid Iron and HY Spreader Sticker. This is the fastest way to green up yellow leaves, but it only affects the leaves that are there, any new leaves will be yellow. Also, this type of application only lasts from weeks to months.
For soil application we have a number of ways to go, depending on what type of plant you are applying to and the location.
First, on Trees a number of Specialists recommend using an auger and making holes near the dripline. Use a 2″ auger and make a 10″ deep hole, fill the bottom 1/3rd with HY Copperas, fill the middle 1/3rd with HY Soil Sulfur, then finish off topping off with FL Garden Cote 6. This is the longest lasting treatment.
For Lawns start with core aerating the lawn, then apply liquid or granule NG Humic. This will help acidify and excite organisms in the soil that will help correct the problem.