Hi, may I inject ferrous fumarate under the bark to treat my Pin Oaks. I've seen lots of references to Ferrous Ammonium Citrate but only a few to ferrous fumarate. I was able to get ferrous fumarate in more reasonable quantity and price, but I don't want to damage my trees by injecting the wrong salt.

Thanks, Mark

Greetings Mark:

I am not familiar with ferrous fumarate, nor have I seen this iron-based compound referenced in the literature for treating plant chlorosis. Therefore, I am somewhat skeptical of its use.

My suggestion would be to stick with the basics as outlined in the literature: iron sulfate, iron chelate, elemental sulfur, ammonium sulfate, etc.

Even though many individuals recommend stem injection treatments, I personally believe ground-based application methods are less intrusive and expensive. Of course, there are certain situations where stem injection methods are applicable and necessary -- especially in areas where ground-based applications are not feasible (numerous urban settings).