How soon can I follow light oil with sulphur?

Sprayed today with spinosad, sticker, and summer oil (3T/gallon of bonide horticultural oil) and noticed a bit of powdery mildew. I’d like to go back and hit those spots with sulphur but don’t know how long to wait. It’s been hot and will be for a few more days.


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Good question and I will be interested in seeing the answers.

Couple of years later I’m wondering the same thing… anybody?

Reason: I sprayed horticultural oil last week on my trees. Today I sprayed sulphur thinking it should be fine since we had 0.75 inch of rain since then. But now I’m worried.

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Sorry to say I still don’t really know- I’ve just made a point of waiting a month between the two of them. In your case that doesn’t help, and the proof will be in the pudding. Sorry you’re being the guinea pig here!


In the grape world it’s 14 days. I’d think a hard rain would lessen that by a few days but it’s not something I’d push…