Controlling grass around fruiting trees and shrubs
When I started planting about 5 years ago, I began with a "farm lawn" and laid out my trees and shrubs in rows, excavating the grass a foot or two around the new planting.
Since then, I have visited a few botanical gardens and wish I done a more careful job because the surrounding grass continues to invade up to the base every year. Each fruit patch has to be mowed in between the individual plants. Not ideal by a long shot.
I'd like to kill the grass in the various fruit patches and find a large supply of (hopefully free) mulch to prevent the reincursion. Meanwhile, is there something I can use to kill established grass now while the fruiting plants are dormant? Temps are in the 40's daytime. I think I read that Roundup needs to be used when temps are in the 70's.
Failing that, how do I improve my situation? I'm leery about digging in close with shrub roots near the surface.