Types Of Edging That'll Prevent Grass From Growing In Flower Beds

A healthy carpet of grass bordered by lush beds of shrubs and flowers is the classic design that many gardeners dream of creating. In reality, keeping the lawn and flower beds neatly separated is harder than it looks. Many grass species are aggressive growers that will inch their way into flower beds no matter how much mulch you put down. Good garden edging can create a physical barrier that stops grass in its tracks, or at least slows it down enough that a little light weeding can keep your lawn under control.

To keep grass from creeping into your flower beds, edging should be deep enough to block rhizomes. Typically, rhizomes grow just beneath the soil's surface, so burying your edging about 1 or 2 inches deep should be enough to keep most grass out. However, some species, like bermudagrass, can send rhizomes as deep as 40 inches to get under barriers. Combatting stolons will be harder. The above-ground stems can slowly stretch across just about any type of edging. Fortunately, they're slow enough that you can keep them at bay by just trimming stray runners as you notice them.

Just about any edging material can create the physical barrier you need to keep grass out, so your biggest considerations should be aesthetics, cost, and how easy it is to install or maintain. From formal brick to manicured hedges, there are plenty of garden edging ideas that make for the perfect landscaping and help keep the lawn out of your flower beds.

Regardless of the edging type you choose, the key to successfully keeping grass out is installing it properly. In general, that means digging a trench around your garden bed that is about 4 inches deep and 4 inches wide, or wider, depending on the dimensions of your edging material. This is deep enough to keep out most grass species, except for very aggressive spreaders, like bermudagrass. Some gardeners simply stop there and let the trench serve as a bed border. This may work, but you will need to re-cut the edge once or twice a year to control the grass that inevitably starts growing over it. A more permanent solution is to fill that trench with a solid edging material. 

Whichever type you choose, be sure to install it securely and backfill the trench well enough to hold it in place. As you push the dirt back into the trench, tamp it down to make sure it has filled in any gaps or crevices and is at least a half inch below the top of your edging material. While lower edging gives you the option to roll right over it with your lawn mower for easy grass control, it's also easier for that grass to climb over. Taller edging will do better at slowing down stolons, but it will mean you have to pull up runners and mats of grass by hand a few times each year.

Brick pavers are great for creating a clean, formal edge around your flower beds that can help slow the spread of grass. While it may not be the cheapest type of edging, you can keep the costs down if you install brick paver edges for your garden beds yourself. 

This is also one of the most versatile solutions for controlling grass. You can stack brick pavers to create a short, charming wall around the bed that also slows the ascent of stolons from bermudagrass and other species that send runners above ground. Alternatively, install a single layer that's level with the ground so the wheels of your lawnmower can roll right along it for easier edge trimming. When installing, you can dig the trench as deep as you like and stack bricks in multiple layers to create a deep underground barrier to help block even the most aggressive of rhizomes. 

While they're versatile and long-lasting, brick or stone borders might not completely block grass from spreading into your flower beds. Grass can find its way through the cracks between bricks or pavers. Taking the time to mortar the pavers when you install it can seal those gaps and create a solid below-ground barrier. However, the process is more labor-intensive than just stacking the pavers and using a little landscape adhesive to hold them in place. Still, if this type of edging best matches your aesthetic, it may be worth considering. 

Corrugated metal is a durable, affordable, and easy-to-install option for your garden. It comes in flexible rolls, like this 20-foot-long Gardzen Landsape Edging Border. Because it's flexible, corrugated metal is easy to contour around any curved edges in your garden. If you have lots of corners or odd shapes to edge in your garden, this solution will be a lot easier to DIY than other types of edging. The solid sheet of metal also has no gaps or cracks for rhizomes and stolons to sneak through. Aggressive spreaders can still try to climb over or dig under the edging, though.

To install corrugated metal edging, all you have to do is dig out a trench around your flower bed, insert the material, and then backfill the trench. The material is available in different heights, so you can install taller or deeper edging, depending on what you need. This means you have some versatility to design an edging solution that's best suited to control the grass species growing in your yard. 

Since corrugated metal is relatively thin, it's a good pick for smaller gardens where you don't want the edging to take up too much space or distract from the garden itself. Just make sure you choose a product made with galvanized metal, which is more resistant to corrosion. While any galvanized metal is fine, opt for steel if you want edging that will stand up to wear and corrosion well.

If you want to achieve a rustic look while keeping grass out of flower beds, consider installing wood garden edging like this Backyard X-Scapes Eucalyptus Fence Border or this HTWNK Bamboo Landscape Edging. Like corrugated metal, this type of edging is often sold in flexible rolls that are easy to install yourself. It's often pricier than metal, but wood edging is still relatively budget friendly. For an even more affordable option, repurpose leftover firewood in your home. Depending on the type of wood edging you choose, you may be left with gaps that grass can send runners through. However, a wooden barrier should still be effective enough to slow grass down if installed well. 

While it looks beautiful and is easy to install, wood edging may not be as long lasting as metal or brick. Wood is an organic material that can rot or become brittle from weather damage over time, sometimes in as little as 2 years. Depending on the type of wood and how it's treated, however, you might get as many as 50 years out of your wood garden edging. Just make sure to do some extra research and be ready to spend a little more on premium materials if your goal is to install edging that will block grass for decades.

For garden edging that keeps grass at bay while serving as a wildlife habitat, consider planting low-growing evergreen or perennial plants that can form a short hedge. This can create a formal yet natural aesthetic that works in just about any garden design. While hedges are often used as larger privacy screens or living fences, low-growing shrubs can create a miniature version of those hedges and help keep grass out.

A compact, evergreen edge can create a solid, deep-rooted border that acts as a dense, shady barrier between your grass and your flower beds. Low-growing varieties of American holly (Ilex opaca) and boxwood (Buxus) are great examples. They're evergreen and can be planted together to form a short, dense hedge. There are also a few slow-growing types of juniper ground cover plants, like 'Blue Star' juniper (Juniperus squamata 'Blue star'), which you can prune into a tidy border.

To minimize the ongoing maintenance required for this garden edging, choose species that are naturally low-growing and compact, so you won't have to prune them to shape as often. Also, opt for native species or at least species that are well-adapted to the light, water, and soil conditions where you will plant them. This will minimize the amount of water or fertilizer you need to use to keep your garden border healthy.