I have two fairly new--3-4 ft.--plums that seems to put out as much folliage at the base as at the top. Do I prune that out now, wait for June, what?
Wait until they are actively growing, or else if you prune when dormant you risk getting water sprouts or other unwanted growth. I read this in the book "Backyard Orchardist"
Here is a link that might be useful: Pruning