Q.Preen
Do you apply Preen on top of mulch or before you spread mulch?

GKH_Susan
Certified GKH Gardening Expert
Certified GKH Gardening Expert
Answered on November 6, 2025
Where you use mulch, apply it on top of the mulch and rake it in to create a protective barrier, per the Preen instructions. In areas where you don't use mulch, just apply it to the soil and work it in with a rake.
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