Rocks, including river rocks and gravel, commonly serve as mulch to help keep weeds from finding a home in flowerbeds. When you cover a rock garden completely in rocks, you have built-in mulch support. Whether your garden has large boulders as part of its design or is low and flat, using color and texture for design, ensure the area is covered completely with small rocks serving as mulch. Scrape the rock mulch about 2 inches away from the trunks of the bushes to help prevent root rot and other fungal infections.
A rock garden adds texture and color to a difficult area of a yard, such as a hillside, and it serves as a focal point. Adding bushes to a rock garden adds a touch of plant life that doesn’t require constant upkeep. When weeds pop up between the rocks, they mar the garden’s appearance, but one or more weed-control options – most notably, landscape fabric under the rocks – can be used to restore the site.
Rocks as Mulch
A post-emergent herbicide kills weeds as soon as they sprout. Choose a non-selective herbicide such as one containing glysophate so it will kill nearly any kind of weed that appears. Care is essential when spraying the non-selective herbicide near your bushes because it can harm or kill bushes as well as weeds. Protect the bushes from herbicide drift by placing plastic or a large piece of cardboard between the bushes and where you spray, and spray only on days that aren’t windy.
Best Weed Barrier Under Rocks
Adding underlayments between the rocks and the soil creates a weed barrier that helps prevent weed seeds from touching the soil. If you already have rocks in place, rake them away temporarily while you install the underlayments. Choose landscape fabric or black plastic as the underlayments.
Commercial herbicides (plant killers). Here we’re talking about products like Roundup, which contain glyphosate. They pretty reliably knock out weeds, even seemingly invincible Bermuda grass. The disadvantage is that many people prefer organic products, especially if they plan to later grow edible plants in the area.
Like many Arizonans, you may have opted for rock landscaping so you don’t have to waste precious water on a lawn. Then a little rain shower comes, and you find a big crop of weeds popping up in your beautiful rock landscape.
MDI Rock supplies a wide range of products for all sorts of uses at competitive prices. If you’re not sure what kind of rock you need or how much, we’re happy to give you our expert advice based on 30 years of experience. We carry over 50 colors of decorative groundcover as well as rip rap, flagstone, topsoil, sand, gravel, and a huge selection of boulders.
Landscape plastic. Some people find this useful, but we see a couple of drawbacks to it. For one thing, you have to lay it down before you put in your rocks, so if you didn’t do this from the beginning, it’s not helpful. The bigger problem is that eventually holes will wear through the plastic, and the weeds will grow through them. Plus, dust will blow on top of the plastic, letting weeds sprout there. So you get weeds anyway, and over time, the plastic will become unsightly as the rocks shift and bits of ragged plastic start to surface.