That's exactly what happened to me, Frank -- I sprayed Sunday night, then it rained Monday morning. My thought, I'm going to spray again about Sunday after the cold front passes.

I don't think this was a waste. Yes, some no doubt washed off. But I look at it this way -- if some washes off, it might be 75% or 50% or 25% effective. If we HADN'T sprayed at all, it is 0% effective. And, most of this stuff isn't THAT expensive anymore, the Once and Done is pretty cheap at least, so it's not like its megabucks going down the drain.

Good to know... This was on 2 plums trees that I know will get hit hard by PC and every year I swear I'm a day late on spraying them.

I think the key is did it have time to dry before the rain.

I hope so. I won't be able to spray again for a week, with all the constant rain. Fortunately, it's too late now for scab here.

It should have had time...its not like it was that humid and there was a light wind.