As experienced gardeners know, fighting weeds is a never-ending battle. They seem to pop up no matter what you do. But there are proven strategies for preventing them, and mulch is one of the best tools available. Working with a professional for your landscaping needs, including mulch application, is the best way to make sure your weed control program works.
For flower beds and landscaping, we like a chipped or shredded bark mulch with a relatively coarse texture. It decomposes relatively slowly and doesn’t blow away so it can do its job and keep sunlight from reaching the soil. Inorganic mulch (like stones or gravel) does an excellent job of preventing weed growth. However, it doesn’t offer the soil-improving benefits of organic mulch.
We often find weed seeds in old or contaminated mulch. Seeds can also get distributed by birds or wind into new beds.
If weeds start popping up in mulch, we want to tackle them before they can seed and spread. If you’re pulling weeds by hand, make sure you get the whole weed, including the root. Applying a pre-emergent herbicide is also an option. One approach is a commercial weed-killer like Roundup, which contains the chemical glyphosate. Some gardeners prefer a more natural approach, using a mixture of vinegar, salt, and dish soap to kill weeds as they grow.
How Can I Kill Weeds in Mulch?
We all know how tenacious weeds can be. They thrive on the very same things your garden does: sunlight, water, and nutrients in the soil. Weeds take pretty much any opportunity to grow and aren’t picky about where they take root. As plant-based mulch decomposes, it provides an attractive, nutrient-rich environment for weeds to take root.
Here are a few strategies for preventing weeds from popping up in your mulch:
Applying mulch every spring makes sense on several levels. It helps enrich the soil and helps retain moisture during the dry summer months. But the main reason most of us mulch is weed control. We faithfully lay down a couple of inches of mulch and cross our fingers that we’ve won the battle. But most of us aren’t so lucky: weeds almost always find a way to pop up, even in the most beautifully mulched landscaping. Why are weeds so hard to tame, and what can you do to stop them? Here are a few tips:
What’s the Best Mulch to Prevent Weeds?
At Epling, our experienced team knows which type of mulch to use in different locations. We apply just the right amount for each job, both for weed control and curb appeal. We have herbicide use down to a science and know which kind to use, both before and after mulching. This spring, put the focus on spending time outdoors with family and let our pros at Epling take care of the weeds.
Make the mulch layer thicker. It is much harder for sun and weeds to penetrate a 4-to 6-inch layer of mulch than it is for them to penetrate a 2-inch layer of mulch.
Treat the ground with a pre-emergent herbicide before adding the mulch. Purchase a chemical herbicide or use an organic herbicide, like corn meal gluten, according to the package instructions.
Mulch is beneficial to plants as well as aesthetically pleasing. Whether you use an organic mulch like wood chips and bark or an inorganic mulch like gravel, mulching maintains soil temperatures and keeps moisture levels higher. Mulch also acts as a weed blocker, preventing the sun from reaching weed seeds and allowing them to germinate. Occasionally, a weed or two does get through the mulch, but a few tips can help the mulch do its weed-blocking best.
Lay sheets of black plastic or landscape fabric under the mulch to add a second layer of protection, keeping the sun from reaching weed seeds in the soil.
Pull weeds that make it through your barriers. If it is possible, pull the weed and the root system when it appears.
Dig out weeds before adding the mulch. Pull existing weeds by hand and dig out stubborn roots with a trowel.
Spot treat weeds if they appear and cannot be pulled. Pour boiling water on the weed to kill it. Alternatively , spray the weed with a post-emergent herbicide, dish soap or pickling vinegar. Pull up the weed once it is dead, or push it down under the mulch.
Think it’s an overstatement to call it the war against weeds? Here’s what you’re up against.
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Frequent, light watering causes shallow roots and helps annual bluegrass, crabgrass, chickweed, sedges and other weed seeds germinate. If you water too little, the lawn suffers while spotted spurge, Bermuda grass, quackgrass and other weeds adapted to drier soil thrive. Instead, provide your lawn with infrequent, deep soakings. Lawns need about 1 inch of water per week. Set an empty tuna can on the lawn to determine when you have applied 1 inch of water.
Can I Put Landscape Fabric Over Weeds?
Spread Landscape fabric and cut it to fit around plants. Photo by Saxon Holt