True or False?: Don't plant annuals under a J Maple as the roots of JM are generally shallow and 'dislike' any disturbance with such disturbance or even 'damage' in the root zone can open up pathways for disease pathogens - like Verticillium wilt; this is not unusual with trees such as JM's.
I avoid digging under the canopy of most shallow-rooted trees like Japanese maples because damaging the roots reduces the tree's ability to access water and nutrients. Current advice to mulch heavily under shrubs and trees would not be compatible with growing annuals either. Could you put a few pots or baskets of annuals here and there under the JMs to achieve somewhat the same look?
Same as Margot ; nothing under the canopy of shallow rooting trees, to which maples fall into that category. I mulch with bark under all my maples, and that's it.
