How to Keep Bermudagrass Out of Flower Beds

circular flower bed

Although Bermudagrass may be great as a lawn, it’s an aggressive, invasive weed when it creeps into flower beds, vegetable gardens, or shrub borders. The easiest way to keep Bermudagrass out of flower beds is to avoid planting this turfgrass altogether. But for many gardeners in the south, Bermudagrass is already well established in their yards. 

So, how can you protect your prized flowers from this pesky weed? In this article, you’ll find tips on how to keep the stealthily creeping Bermudagrass out of your garden beds and how to react promptly when it pops up.

How to Keep Bermudagrass Out of Flower Beds

Bermudagrass grown in a lawn
Photo Credit: Pexels

Step 1: Create a Barrier for Bermudagrass

Consider either plastic or metal edging that is at least 10 inches tall. That allows you to sink the edging into a 6-inch-deep trench, with 4 inches above the soil line.

The stems of Bermudagrass run about 6 inches deep, so a trench and edging at that depth should deter an underground invasion. 4 inches of edging above the soil should keep the runners from going over the top. However, the runners are a galloping bunch. They’ve been known to run across a 3-foot-wide sidewalk to get to the other side.

Your barrier will be no good if the Bermudagrass grows tall and develops seed, so remember to mow alongside the edging regularly. Seeds are seeds and they will drop to the ground or be spread by wind, birds, and other wildlife. Keep the grass at 1 ½ to 2 ¼ inches inches tall, well below the 4-inch edging barrier.  

Step 2: Create a Grass Buffer Zone

Whether you’re creating a new garden bed or protecting an existing one, a buffer zone can help keep the Bermudagrass at bay.  The buffer zone goes between the garden bed and the Bermudagrass lawn, acting as a trap for encroaching Bermudagrass before it reaches the edged garden bed. This makes it easy to spot and pull Bermudagrass before it spreads too far.

Be as meticulous as possible about clearing grass and weeds when creating the buffer zone. This might be a time to consider using a weed killer or herbicide, such as glyphosate to get a handle on the Bermudagrass. The non-selective herbicide is sold as Round Up or Ornamec, among other brands. Some herbicides are labeled specifically to control Bermudagrass in the lawn without killing other grass. Be sure the product is labeled for use on Bermudagrass. Always read and follow the label directions.

Don’t want to use synthetic chemicals to control the bermudagrass? Here are some low cost, eco-friendly solutions, but the process is slow.

Option 1: Smother Bermudagrass

Mow or use a weed eater to cut the grass as close to the ground as possible. Wet the area. Place a single layer of cardboard over the area.

Overlap the edges of the cardboard by about 6 inches to prevent the grass from creeping through to reach the light. Use lawn staples to hold the cardboard in place. Add a couple of inches of mulch over the cardboard. Eventually, the cardboard will disintegrate, smothering Bermudagrass as it does.

Option 2: Cook Bermudagrass with Plastic

Wet the area to be covered. Lay black polyethylene over the Bermudagrass in summer. Leave it there for six to eight weeks to kill the existing Bermudagrass and roots. Keep it as close to the ground as possible, without gaps or holes; otherwise, Bermudagrass will find a way to emerge from the black plastic.

You can also cook up the bermudagrass with clear plastic. After you’ve mowed or weed whacked the Bermudagrass and weeds as close to the ground as possible, wet the area. Then place clear UV plastic on top of the cleared area. The clear plastic should extend 24 to 30 inches beyond where the Bermudagrass is. 

Step 3: Be Diligent at Pulling Grass

Even after you’ve installed the edging and created the buffer zone, you won’t be able to rest for long. Anytime you see Bermudagrass poking through the buffer zone, hand pull it or treat it with an post-emergent herbicide, such as glyphosate. Remember glyphosate is a non-selective herbicide, so it may also kill desirable plants. Always read and follow the label directions.

Why is Bermudagrass Bad for Flower Beds?

Bermudagrass earns its invasive description by its three-way attack. It spreads by underground stems called rhizomes. It spreads by above ground stems called stolons or runners. And it spreads by seed. As Bermudagrass spreads, it can quickly overwhelm or strangle desirable plants. Plus, turfgrass in a flower bed gives it an unkempt look.

What Can You Plant Instead of Bermudagrass?

The best alternative depends on where you are in the country. Buffalo grass, zoysia grass, or tall fescue may be good choices. For the best recommendation on turfgrass recommended for your area, contact your local cooperative extension office.

Call a Lawn Pro

Contact a local lawn care pro to help manage the lawn, no matter what kind of grass you grow. The pro can keep Bermudagrass in check by trimming along the buffer zone.

Main Image Credit: Stanley Howe, CC BY-SA 2.0

Jo Ellen Meyers Sharp

Jo Ellen Meyers Sharp

Jo Ellen Meyers Sharp award-winning garden writer, editor, and speaker. (She speaks at libraries, garden clubs, public gardens, home and garden shows, Master Gardener groups, and horticulture industry events.) Known as a hortiholic, she frequently says her eyes are too big for her yard. She blogs at hoosiergardener.com.