Hello Anthony,

You said that the regimen of fungicides “worked” but you have fungus (leaf spot) problems on your lawn every year. Did the fungicides really work? The spores for leaf spot and rust are in the soil essentially every year. Whether or not there is a outbreak depends on the environment being favorable for the spore growth. So we need to consider whether the fungicides worked or were the conditions not favorable for fungus growth?

A couple of things about organic products. (1) Organic is not equivalent to “safe” or “non-toxic” it simply means “occurring naturally”, and (2) when a company claims effectiveness of an organic product, it does not need to provide any test data or proof to corroborate claims of effectiveness.

When I look at the sulfur wettable powders, there is no dosage on the label for applying on lawns, so we cannot comment on its use as that is “off-label.”

I've also found Southern Ag "Garden Friendly Biological Fungicide" (Bacillus amyloliquefaciens strain D747* - 98.85%). This does have directions for use on lawns, so you can follow the directions on the label.

The John and Bob’s website says it can be used on lawns but I could not find a label to corroborate that. If there are directions for lawn applications on the label, follow them.

I have studied organic lawn products for several clients on this service. Unfortunately, I have not found any research based studies utilizing organic fungicides. I cannot offer you any suggestions for using these products on your lawn.

I do not know the size of your lawn, but have you considered researching turf grass varieties that are more fungus resistant? Ultimately this might be the most effective way to avoid the yearly ravages of fungus on your lawn.