Dormant Spray and Whitewash

Question

I have a couple young cherry trees in pots that seem to have a shothole fungus problem, which I'm told I can clear up by treating with a dormant spray after all the leaves fall off. I would also like to paint the trunks white to help protect them from sunburn, as I need to move them to a new location that will give them a lot more direct sun.

My question is can I apply both in the same winter season? Should I spray the dormant oil before or after painting them white? If I spray the dormant oil first, will that cause any issues with the paint job adhering? Or, can the dormant spray solution be mixed into the white latex paint mix to apply both at once?

Answer 1

Because paint has the possible effect of interfering with gas exchanges through the bark, I wouldn't recommend doing it until the bark breaks, and roughens with age. I wouldn't expect much trouble though. You could also use trunk wraps. I would spray the oil on first, so that it will affect the fungus that will otherwise be covered by paint. If you wait until the dormant spray dries, the paint won't have any adherence issues.

Make sure you rake up and remove all the fallen leaves, as they will be carrying the disease. When you spray, be sure you get all sides of all the branches. People tend to underspray dormant sprays, and the diseases won't die if you miss. I never tried mixing spray and paint. I wouldn't, because usually paint mixes become unbalanced easily, and you might case it not to stick/dry well. If you try it, use a small amount first, and apply to a small area. Use spray concentrate. If it sets well, it should be just as effective as spray.