Bonide sulfur

Anyone use this product? I can not find lime sulfur but can find this. It says it can be sprayed. But curious about it’s effectiveness compared to lime sulfur.

I sprayed copper around Thanksgiving but was thinking about spraying this instead of another round of copper. Or maybe both? It says not to spray within 3 weeks of dormant oil. But doesn’t mention copper.

Here’s the label:

The label gives good info regarding how much to use and when with each fruit. But I’m also curious how well this works, especially in comparison to lime sulfur.

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The label demonstrates that it is 90% pure powdered sulfur. Agriculturally this is a good choice in orchards with sufficient or excess Calcium. Hopefully someone here has experience with powdered sulfur.

lime-sulphur penetrates tissues so is an eradicant to some degree. Sulfur rests on the surface so is more protective. So, they are somewhat different and don’t completely substitute for one another. I think Seven Springs is selling lime-sulfur in larger quantity now.

I’ve been wanting to order the REX Lime Sulphur from 7 springs, but it is mentioned that it also works as a thinner for apples. I’m assuming that this works only when sprayed during full bloom and maybe at a higher concentration but I don’t want to take a chance given how difficult it is to produce fruit at my site. Does anyone have more knowledge of lime-sulphur’s thinning properties?

What are you looking to use sulfur against?

Bonide sulfur and other wettable-powder forms of sulfur (Cumulus WP, etc), as Scott says, are protectants. Sulfur is primarily a protectant for apple scab in an organic spray program. The chemical form is elemental sulfur aka S(0), or rhombic S8.

I use Bonide sulfur extensively for apple scab. It works just fine for that if you watch the weather and infection periods. You don’t start to spray sulfur until there is green tissue as it only protects locally on the leaf surface.

I doubt sulfur is effective for peach leaf curl (it isn’t on the label).

It is also hard for me to believe that sulfur powder would be effective for fireblight.

Lime sulfur really is a completely different beast. From a chemistry prospective calcium polysulfide is what you get when you react highly toxic hydrogen sulfide (H2S) with sulfur (S8) in the presence of calcium hydroxide. Polysulfide is Sx2- (where x is a subscript from x = 2 to about 7 or 8, and 2- is the charge on the chain). The reaction is fairly reversible, and the polysulfide easily reverts to S8 and H2S. The nice part about it is that you get a contact toxicant that likely slowly converts to very fine and well-distributed S8 that acts as a protectant.


I just read a comment by Dr Linda Chalker-Scott in the Garden Professors Blog stating that Lime-Sulfur is no longer legal for home gardeners. (Others commented that it seems to continue to be readily available). How might this affect availability in the future for home orchardists?

There was a discussion awhile back and my recollection is its not illegal but due to its use for illicit activities the makers did not renew their licenses. You can only buy it in bulk now from orchard supply places.

@ztom, if you don’t spray it around bloom it won’t do any thinning. I have used it as a dormant spray for many years and I don’t think it thinned anything.

This year I had a bottle leak and I discovered too late … there was crystal sulphur on everything and it took me a long time to clean it all off. I also must have been gassing my whole garage with H2S, fortunately slow enough as I never smelled it. The stuff is definitely toxic and H2S is a highly toxic gas.

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My understanding from “back in the day” is that as long as you can smell that rotten egg smell you’re not in great danger, but that as the gas concentrations rise there is some kind of anesthetic effect on the nose and then you’re at real risk; the toxicity is actually comparable to cyanide gas at that point. So yeah- pay attention!