Recently I have been studying various nutrient deficiencies among citrus. Coincidentally, I repotted all of my citrus to CHC. Shortly thereafter, I noted the unique pattern of magnesium deficiency in some of my newer trees. I treated with a little epsom salts, and so far no improvement.

Then I came across this link: http://www.ladyslipper.com/coco3.htm

This link describes the use of CHC in orchid culture. Their washing procedure includes the use of magnesium sulfate (epsom salts) and calcium nitrate to ward off a transient deficiency in calcium and magnesium. An explanation/rationale is included.

Has anyone noted a transient magnesium or calcium deficiency after repotting? Does anyone modify their CHC washing procedures? Thanks. Robert

Nope. The first thing I add into any potting media are iron sulfate, magnesium sulfate and a dose of 6-20-20XB with minors from BEST.

Robert, I have always pre-treated CHC's exactly the way that your link suggest, when I pre-soak . Note that most all complete water soluble fertiizers, even fertilizers that also contain trace minerals, rarely include any magnesium in the formulation. I always add magnesium, in the form of epsom salts, to my fertilizer solutions. Your tree's leaves that are already showing the characteristic green wedge shape at the bottom of the leaves that are deficient of magnesium, will stay that way for some time. However, now that you have corrected the situation, with the addition of epsom salts, all new leaf growth will again begain to grow with the normal healthy green coloration. Always check the fertilizer label to see if any magnesium is included in the formulation. If none is added, it rarely is, you must add it yourself. - Millet