Having had to drop Chemistry 101 in college due to lack of comprehension, this thread is very instructive. I remember hearing from organic farmers that sulfur is anathema to microbial life (sulfa drugs are antibiotics). They suggested that to have a vital soil, less sulfur (in the form gypsum) should be applied. I would like to hear more about this from knowledgeable folks like Jim. J.E. Shields wrote: > It isn't advisable to use any fertilizer containing > chloride on plants that have any sensitivity to chlorine. What plants are these? I suppose I could google, but its so much easier to ask... Brook Klehm, Seattle, Washington, USDA 8 (so they say)