If you have established trees with these symptoms, there is another option. Lowering soil pH with sulfur can take time, but it targets the cause of the problem. It is best to test your soil before applying any element, especially if it has been more than 5 years since your last test. If you are sure you have iron chlorosis, you may choose a broadcast application of 1-2 pounds sulfur at the dripline of affected trees. I suggest you water trees promptly after treatment to incorporate the product and reduce burning of turf.
This may be done up to twice a year and will help acidify soil. Depending on how high the pH, you may have to apply sulfur over many years. If you have any questions, feel free to call our office at 405-321-4774 or email a Cleveland County Master Gardener at email@example.com.
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