I have 2 plum trees that I planted last year. I just checked them and they have a split in the branches that I believe to be a canker (fungi). What shold I do? The dormant oil that I use on my apple trees does not list plums on the lable.
Certified GKH Gardening Expert
The dormant oil you have should be fine for the plum tree. I can't say 100 percent for sure, because I don't know exactly the brand you are using, so you may want to call where you bought it at and ask a nursery worker to confirm that it is safe for plums.