I have several large beds in which I would like to plant shrubs, perennials, and some annuals. I am wondering what, if any, weed barrier I should use for these beds. I have heard different opinions advocating weed fabric, newspaper, or no weed barrier at all other than a layer of bark/mulch. If a thick layer of mulch alone is virtually as effective as weed barrier, I would rather avoid the expense and hassle of laying the barrier. Which is the best option?



In many instances including when you are going to be planting annuals in a landscape bed, fabric or plastic weed barriers are not a good option.  A hole must be cut for every plant.  This creates an opportunity for weeds to penetrate the barrier.  Where annuals are planted can vary from year to year and more holes would have to be made to plant in these new spots.  Fabric barriers are best used in beds where shrubs and trees are planted only.  This minimizes the amount of holes that will be cut.

Two to three inches of mulch will eliminate much weeding and conserve water, but it is not a perfect solution either.  You still may need to use a pre-emergent weed killer such a treflan, surflan, barricade or gallery to eliminate seeds that are are still in the soil or tha tshow up after the fact due to wind and/or irrigation.  You also may occasionally may need to spot treat weeds with an herbicide.

Some keys to keeping the weeds at a minimum is to apply the appropriate amount of mulch.  Keep in mind that too much is also detremental to landscape plants.  Additionally, disturb the bed as little as possible once it is planted when you apply a pre-emergent weed killer.  If possible, only water desirable landscape plants and not the entire bed.  Most weeds need water to grow.

Posted on 27 May 2009

Taun Beddes
Horticulture Agent, Cache County

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