Ferrous sulfate deficiency in trees can cause a condition known as ferrous chlorosis. The typical symptom of ferrous deficiency is yellowing of the foliage, often with the veins remaining green. The problem of ferrous deficiency usually results from soil that is too alkaline or otherwise not compatible with a specific tree species. An ferrous sulfate solution can be sprayed on the foliage for a short-term solution to combat the yellowing associated with ferrous-deprived leaves. A foliar application of ferrous sulfate offers the fastest color change in the foliage, but the results are usually short-lived and reapplication is often needed.
To correct Fe deficiency by spraying you need to prepare the following things:
With the above things and then we can start to spray by the following guidance:
1. Mix 2 oz. of ferrous sulfate with three gallons of water in the pressurized spray pump, according to the manufacturer's directions. This solution makes the recommended 0.5 percent
solution. Add two to three drops of dish detergent to act as a wetting agent to help the solution stay on the foliage longer.
2. Spray the tree's foliage on a cool cloudy day when possible, or spray in the evening when temperatures are at the lowest to avoid burning the leaves. Wet the leaves thoroughly with the ferrous solution, working from the top of the tree downward.
3. Check the tree in one week for signs of new leaf growth, and for improvement in the color of the older foliage. Spray the entire tree again with ferrous sulfate solutions if the foliage is not greening-up, or only apply the spray to any new growth that has developed. The process may need to be repeated several times during the tree's growing season for adequate greening of the foliage.