Answer: Round Up can hurt the roots of your trees and shrubs so don't use it to kill any weeds beneath them. It's a contact killer and can harm any shrubs or perennials in the vicinity. Instead, dig the weeds up, roots and all so you have a clean slate, then lay your weed barrier fabric and mulch over the clean soil. The combination of the weed barrier fabric and a few inches of mulch will keep weed seeds from germinating and your trees and shrubs will be weed free for several years.
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