How to Prevent Weeds From Growing in Your Mulch Bed

Frequently Asked Questions

Nobody likes to pull weeds. While some weeds will inevitably germinate and need to be sprayed or pulled, a few simple things can be done to prevent these issues. 

How do I prevent weeds when creating a new mulch bed? 

One way to prevent weeds when creating a new bed is to use landscape fabric. Once trees, plants, and/or flowers are planted and bed edges are cut, laying down landscape fabric prior to mulching will prevent the germination of weeds. The fabric, which can be purchased at any garden supply store or online, is easy to cut to size for installation. Depending on the thickness of the material, it will last anywhere from 2 to 5 years in most situations. 

How to prevent weeds in an existing mulch bed? 

If weeds are present in an existing bed, they must first be eradicated. Pull weeds that may have germinated within or directly next to ornamental plants and spray a product containing glyphosate on the weeds. As always, take care when using these products, as they are absorbed via the foliage of a plant and should not contact any ornamental plants. 

Once the bed is rid of weeds, a granular pre-emergent product should be applied throughout, which can be purchased online or in any garden supply store. There are numerous brands of granulated pre-emergent, but the product should have an active ingredient labeled as prodiamine or pendimethalin. This product, as it is watered in, will form a barrier within the soil and prevent the germination of future annual weeds. 

Does mulching prevent weeds? 

Perhaps the simplest way to keep weeds out is to apply a layer of quality mulch. Not only does mulch help retain moisture, but the barrier created will serve to keep weeds at bay as well. Most homeowners prefer a double or triple shredded hardwood mulch that has been dyed. The dye, which come in many colors, will help the mulch to retain its color for up to a year. Two to three inches is all that is needed to help prevent future weeds. 

Is there a way completely get rid of weeds in my mulch bed?  

Despite the above techniques, nothing is going to be completely successful at keeping weeds out of your beds. The pre-emergent application will break down after 5-6 months and will have to be repeated. Furthermore, it only prevents annual weeds from germinating. Perennial weeds, such as nutsedge, cannot be prevented using this measure and must be dealt with by utilizing glyphosate or hand pulling. Mulch normally needs to be reapplied yearly after it begins to break down. However, mulch should never be applied more than 3 inches deep, as too much mulch can begin to smother the base of plants or trees. Following these tips will allow you to enjoy your landscape and spend far less time dealing with weeds.