How to Safely Remove Bermudagrass From St. Augustine Lawns

by Jamie Tedder December 3, 2024

Discovering that a different type of grass is invading your well-established St. Augustine lawn can be a frustrating experience. If you see bermudagrass creeping in, you should act quickly before the issue worsens. With its broad blades, St. Augustine is widely favored in Florida lawns, but bermudagrass—with its aggressive growth habit—can quickly take over. Its invasive nature causes it to compete for resources, often at the expense of your St. Augustine grass. If left unchecked, bermudagrass will spread rapidly, disrupting your lawn’s uniform look.. In this article, we’ll provide steps to remove bermudagrass from St. Augustine lawns, helping you restore a lush, green look.

The Problem with Bermudagrass in St. Augustine Lawns

Bermudagrass spreads vigorously through stolons and rhizomes, which allows it to invade and cover large areas of your lawn quickly. These runners, which grow horizontally above and below the surface, put down new roots and continue to spread in all directions. This aggressive spreading habit makes bermudagrass challenging to control once established. In optimal conditions, it can overtake an area in as little as a few weeks, outcompeting other grasses, including St. Augustine.

On the other hand, St. Augustine grass is known for its broad, wide blades and its ability to thrive in both sunny and shaded areas, making it a great choice for lawns with mixed conditions. On the other hand, bermudagrass prefers full sun and performs poorly in shaded environments. The stark contrast in their ideal growing conditions is one reason these two grasses don’t mix well. While St. Augustine thrives in a variety of conditions, bermudagrass is a sun-loving grass that can quickly outcompete St. Augustine in areas where the latter is stressed or struggling.

St. Augustine and Bermudagrass: Why They Don’t Mix Well

When bermudagrass begins to invade a St. Augustine lawn, the result is often a patchy, uneven appearance. This occurs because the two grasses have different maintenance needs. St. Augustine struggles in conditions bermudagrass can tolerate, such as consistent, high foot traffic or soil compaction. With its aggressive growth habit, bermudagrass quickly spreads to these weakened areas, outcompeting St. Augustine for space and resources.

St. Augustine cannot recover independently without intervention, and bermudagrass will continue to dominate. Once the Bermuda starts to invade, reclaiming the lawn is difficult unless you remove the bermudagrass altogether and replant new St. Augustine grass plugs. In cases where bermudagrass has taken over a significant portion of the lawn, controlling Bermuda becomes an urgent task to prevent it from spreading further.

If you're curious about mixing bermudagrass with St. Augustine grass, check out our guide on Can You Mix Bermuda and St. Augustine Grass?

How to Get Rid of Bermudagrass From St. Augustine Lawn

Removing bermudagrass from a St. Augustine lawn presents a unique challenge. Because these grasses belong to the same family, the same herbicides that can kill bermudagrass will also kill the surrounding St. Augustine grass. Therefore, conventional methods for controlling grassy weeds will not work here. Bermudagrass is persistent—if even a tiny piece is left behind, it can easily spread again through its runners.

While you can try manually pulling the grass, this method can be ineffective, particularly if the bermudagrass has deeply established roots. It's essential to be meticulous and remove every trace of it to prevent regrowth.

Step 1: Kill Bermudagrass and Surrounding St. Augustine

The best approach is to kill the bermudagrass along with enough surrounding St. Augustine grass using herbicide, ensuring that all bermudagrass runners are removed. Apply the herbicide to the affected areas and let it work for several days. Once the bermudagrass has died, carefully remove the dead grass and dig up and discard any remaining runners.

Step 2: Replant with SodPods Grass Plugs

Once you've removed the bermudagrass, you can then replant the affected area using a sod tool to help plant grass plugs. Grass plugs are an excellent solution for repairing bare patches left behind by the bermudagrass. As mature grass with well-established roots, plugs allow for faster coverage, filling the bare spots and helping prevent further invasion from bermudagrass. They’re also less prone to being overrun by other grassy weeds, as their roots form a dense, resilient network. For best results, use NutriPod grass fertilizer, which has a 17-1-10 NPK ratio, formulated to double the growth rate of new grass plugs.

Step 3: Maintain a Healthy St. Augustine Lawn

Keeping your St. Augustine lawn healthy and thriving is the key to preventing bermudagrass from reinvading. A well-maintained lawn is better able to compete with invasive grasses.

Mow at the Highest Setting: Bermudagrass prefers low mowing heights, so cutting your St. Augustine grass at the highest setting on your mower will discourage bermudagrass growth. This creates an environment that favors St. Augustine and allows it to grow thick and strong.
Water Weekly: St. Augustine grass needs about 1 to 1.5 inches of water weekly to stay healthy. Increase watering times during dry spells or when your lawn appears stressed. Proper hydration helps your lawn grow strong and dense, making it more difficult for bermudagrass to take hold.
Fertilize and Aerate Regularly: Fertilize your lawn with a balanced fertilizer to provide the nutrients St. Augustine grass needs. Aerating the lawn also promotes root growth and allows water and nutrients to penetrate the soil more effectively, supporting a healthy, thick lawn.

If the bermudagrass has spread extensively and grass plugs can’t fill in the areas quickly enough, consider laying fresh St. Augustine sod instead. Sod provides an immediate solution and helps quickly restore your lawn, preventing bermudagrass from taking hold again. Whereas grass plugs are effective for small repairs, sodding is ideal for larger areas that have been heavily affected by bermudagrass.

Final Thoughts

St. Augustine grass is a favorite option among Florida homeowners, especially in areas with mixed conditions such as sun and shade. Its dense, lush appearance and ability to thrive in various environments make it a preferred turfgrass for many lawns. However, with its aggressive growth habit, bermudagrass is not ideal for lawns that already feature St. Augustine. While bermudagrass has its place in certain yards, it can quickly overtake a St. Augustine lawn if allowed to invade.

Following the steps outlined in this article, you can safely remove bermudagrass from your St. Augustine lawn and restore it to its original health and appearance. Maintaining a healthy lawn with proper mowing, watering, and fertilization techniques will help keep bermudagrass at bay. If your lawn has already been heavily affected, consider using grass plugs to repair the damage and ensure that St. Augustine remains the dominant grass type in your yard. With timely intervention and proper lawn care, you can reclaim your lawn and prevent bermudagrass from taking over again.

Jamie Tedder

Jamie surrently serve as Vice President on the board for Turfgrass Producers of Florida. He currently oversees the production of all grasses throughout all farms in Florida at Bethel Farms. He is actively working with top grass breeders, researchers, producers and end users from public and private institutions around the country to stay up to date on current industry developments. Being a University of Florida graduate, he has applied that knowledge to over 22 years of experience growing spectacular grass!