should preen be watered in
Use the same amount of Preen regardless of whether youâre applying it directly onto the soil or on top of the mulch. Apply Preen when the garden is dry; if you apply when wet the granules could stick to the leaves. This can cause leaf damage or discoloration. Itâs very important to water in Preen.Water activates Preen. You may water with a hose, or sprinkler, or rain if a soaking rain is expected within the next day or so. After you water in any new application, donât allow people or pets to walk in the bed until it is once again dry.reen garden weed preventers stop weeds when they're seeds. Here's the short course on getting the jump on weeds. Applying Preen Weed Preventer 79296 views. You can start your Preen routine any time before or during the growing season.