I planted four young plum tree this spring and was hand watering them every day until recently I started using a sprinkler. Last night I noticed what appears to be Cherry Leaf Spot on one of the trees. There is a lot of information about the fungus that causes this and how to prevent, but not a lot about whether using an anti-fungicide spray right away will help or do I need to wait until the end of the season. And, I'm a newbie so this question may be fairly basic: do I need to change the way I water the trees (i.e., stop using a sprinkler) to help prevent in the future?
Thanks in advance for any help.
