I just used it on a fig (El Molino) that seemed to have a rust problem. All the leaves were in really bad shape. I sprayed right from the bottle, per the directions. The then sprayed another 5 days later. The new leaves that have emerged since the spraying look great, and the plant as a whole, does look much better. It is on my deck with really intense sun and heat. I sprayed early morning, then tried to keep it shaded as best I could for about a week. I was just guessing, but I maybe I got lucky.