Blending Bermuda grass with St. Augustine grass creates a lawn with competing growth habits and maintenance needs. If you are thinking about mixing bermuda grass with st augustine grass, you need to know that these two turf types do not naturally coexist. They have different textures, colors, and growth patterns that clash visually and functionally.
Most lawn care experts will tell you to avoid this mixture entirely. However, sometimes it happens by accident, or you might be dealing with a patchy lawn and wondering if you can just throw down some seed to fix it. Let’s look at what really happens when these two grasses meet.
Mixing Bermuda Grass With St Augustine Grass
When you attempt to combine these two species, you are setting up a turf war in your yard. Bermuda grass is an aggressive, creeping grass that grows horizontally and vertically. St. Augustine grass is also a spreading grass, but it is much coarser and grows taller. They do not blend into a uniform carpet.
The result is usually a patchwork of different shades of green and varying leaf widths. This makes the lawn look unkempt and uneven. It is not just about looks, either. The two grasses have different watering needs, fertilizer schedules, and mowing heights. You cannot treat them the same and expect both to thrive.
Why The Mixture Usually Fails
Bermuda grass loves full sun and high heat. It goes dormant and turns brown when temperatures drop in the fall. St. Augustine grass also loves heat, but it can tolerate a bit more shade. It stays greener longer into the cooler months. This difference alone will make your lawn look strange for half the year.
Mowing height is a major issue. Bermuda grass should be mowed low, around 1 to 1.5 inches. St. Augustine grass needs to be cut higher, usually between 2.5 and 4 inches. If you mow low for the Bermuda, you will scalp the St. Augustine and stress it out. If you mow high for the St. Augustine, the Bermuda will become leggy and thin.
Growth Patterns And Competition
Bermuda grass has a very aggressive root system and stolons that run above ground. It will invade the St. Augustine turf quickly. It steals water and nutrients from the soil. Over time, the Bermuda will choke out the St. Augustine in sunny areas.
In shaded areas, the opposite happens. St. Augustine can survive with less sunlight, while Bermuda will thin out and die. So you end up with a lawn that is constantly shifting. The balance changes every season depending on the weather and how you care for it.
Can You Manage A Mixed Lawn
If you already have a mixed lawn, you might be looking for ways to manage it. It is possible to keep both grasses alive, but it requires constant attention. You will need to pick a compromise on mowing height and watering. This means neither grass will look its best.
You also need to adjust your fertilization routine. Bermuda grass needs more nitrogen to stay green. St. Augustine needs less, but it needs it more frequently. Over-fertilizing St. Augustine can lead to disease problems. Under-fertilizing Bermuda will make it weak and pale.
Mowing Strategies For Mixed Lawns
Set your mower blade to a medium height, around 2 to 2.5 inches. This is not ideal for either grass, but it is the best compromise. You will need to mow more often to keep the Bermuda from getting too tall. Do not remove more than one-third of the leaf blade at a time.
Keep your mower blades sharp. Dull blades tear the grass, which makes it more susceptible to disease. This is especially important for St. Augustine, which has thick stems that are hard to cut cleanly. You should also bag your clippings if you have a lot of Bermuda growth.
Watering Requirements
Bermuda grass is drought-tolerant and prefers deep, infrequent watering. St. Augustine grass needs more water and cannot survive long dry spells. If you water for the St. Augustine, you are giving the Bermuda too much. This can lead to shallow root growth and fungus issues.
Try to water deeply but less often. This will help the St. Augustine roots grow deeper. The Bermuda will also benefit from this, but it might get too much moisture. Watch for signs of fungal diseases like brown patch, which loves wet, humid conditions.
How To Remove One Grass Type
If you decide that the mixed lawn is not working, you have two options. You can remove the Bermuda grass or remove the St. Augustine grass. Removing Bermuda is harder because it is so aggressive. Removing St. Augustine is easier but leaves you with a Bermuda lawn.
To get rid of Bermuda grass in a St. Augustine lawn, you can use a selective herbicide. Look for products containing fluazifop or fenoxaprop. These chemicals target Bermuda grass without harming St. Augustine. You will need to apply them multiple times over several weeks.
Steps To Kill Bermuda Grass
- Wait for a warm, sunny day with no rain in the forecast.
- Mix the herbicide according to the label instructions.
- Spray the Bermuda grass patches thoroughly.
- Wait two weeks and check for regrowth.
- Reapply the herbicide to any surviving areas.
- Monitor the lawn for several months to catch new sprouts.
This process takes time. Bermuda grass has a large root system that stores energy. You need to deplete that energy by killing the top growth repeatedly. Be patient and do not skip applications. Missing one treatment can set you back weeks.
Removing St Augustine Grass
If you want to keep Bermuda grass, you need to remove the St. Augustine. This is easier because St. Augustine does not have deep roots. You can dig it out manually or use a non-selective herbicide like glyphosate. Be careful, because glyphosate will also kill the Bermuda.
You can use a physical barrier to separate the two grasses. Install edging that goes at least 6 inches into the ground. This prevents the Bermuda stolons from creeping into the St. Augustine area. However, this only works if you keep the barrier maintained.
Preventing The Mixture From Happening
The best way to deal with this problem is to prevent it. Do not plant Bermuda grass seed in a St. Augustine lawn. The seeds will germinate and create patches. Also, be careful when buying sod. Make sure it is pure St. Augustine and not contaminated with Bermuda.
If you live near a neighbor with Bermuda grass, you need to create a barrier. Bermuda spreads easily across property lines. A deep edging or a gravel trench can help stop the spread. You should also check your lawn regularly for any stray Bermuda patches.
Choosing The Right Grass For Your Yard
Before you plant anything, consider your climate and yard conditions. If you have a sunny yard with high foot traffic, Bermuda grass is a better choice. It is durable and recovers quickly from damage. If you have a shady yard, St. Augustine is the way to go.
Think about your maintenance preferences. Bermuda grass needs frequent mowing and fertilization. St. Augustine needs more water and is prone to pests. Neither is low-maintenance, but they have different demands. Pick the one that fits your lifestyle.
Alternative Grasses To Consider
If you want a uniform lawn without the hassle of mixing, consider other grass types. Zoysia grass is a good alternative. It has a medium texture and can tolerate some shade. It is slower growing than Bermuda, so it needs less mowing. It also handles foot traffic well.
Centipede grass is another option. It is low-maintenance and requires little fertilizer. It prefers acidic soil and does well in the Southeast. It has a lighter green color and a coarse texture. It is not as durable as Bermuda, but it is easier to manage.
Transition Zones And Climate
Your location matters a lot. Bermuda grass is a warm-season grass that thrives in the South. St. Augustine is also warm-season but is less cold-hardy. If you live in a transition zone, you might have trouble keeping St. Augustine alive through the winter.
In cooler areas, you might consider overseeding with ryegrass in the winter. This gives you a green lawn year-round. However, you cannot overseed a mixed lawn easily. The ryegrass will compete with both Bermuda and St. Augustine for space.
Frequently Asked Questions
Can Bermuda grass overtake St Augustine grass?
Yes, Bermuda grass is much more aggressive. It spreads faster and has a deeper root system. In full sun, Bermuda will quickly invade and overtake St. Augustine patches. The only place St. Augustine can fight back is in shaded areas.
What is the best time to fix a mixed lawn?
Late spring or early summer is the best time. Both grasses are actively growing during this period. This makes them more responsive to treatments. Avoid doing major renovations in the fall when the grasses are preparing for dormancy.
Will adding sand help Bermuda grass grow in St Augustine?
No, adding sand is not recommended. It can change the soil structure and lead to drainage problems. Both grasses prefer well-draining soil. Instead of sand, focus on proper aeration and organic matter to improve soil health.
Can I use a regular lawn mower on a mixed lawn?
Yes, you can use a regular mower. Just adjust the height to a medium setting. Make sure your mower blades are sharp. You might need to mow more frequently to keep the Bermuda from getting too tall.
Is it cheaper to mix seeds or buy separate sod?
Mixing seeds is cheaper upfront, but it creates more problems later. You will spend more money on herbicides and treatments to fix the mess. Buying separate sod is more expensive but gives you a clean, uniform lawn from the start.
Final Thoughts On Mixing Turf Types
Mixing bermuda grass with st augustine grass is rarely a good idea. It creates a lawn that is hard to maintain and looks uneven. You will constantly fight to keep one grass from taking over the other. The time and money you spend on fixing the problem is not worth it.
If you already have a mixed lawn, you can try to manage it. Use a compromise mowing height and adjust your watering schedule. But be prepared for a lawn that never looks perfect. The best solution is to choose one grass and stick with it.
Take the time to evaluate your yard conditions. Look at the sunlight, soil type, and how you use the lawn. Then pick the grass that fits best. A single, healthy turf type will always look better than a struggling mixture. Your lawn will be greener, denser, and easier to care for in the long run.
Remember that grass is a living thing. It responds to how you treat it. Give it the right conditions and it will thrive. Mixing incompatible species only creates stress for the plants and for you. Keep it simple, pick one grass, and enjoy a beautiful lawn.
If you are starting from scratch, do it right the first time. Prepare the soil well, choose quality sod or seed, and install it properly. This will save you from headaches later. A little planning now can prevent years of frustration with a patchy, mixed lawn.
Dont forget to test your soil before planting. This tells you what nutrients are missing. You can then amend the soil to give your grass the best start. Healthy soil is the foundation of a healthy lawn. It makes your grass more resilient to pests, diseases, and drought.
Watering is also key. Newly planted grass needs frequent, light watering. Once established, you can switch to deeper, less frequent watering. This encourages deep root growth. Deep roots make the grass more drought-tolerant and stronger overall.
Fertilize according to the needs of your chosen grass. Too much fertilizer can burn the roots. Too little can starve the plant. Follow the recommended schedule for your specific turf type. This will keep your lawn green and lush without causing problems.
Pest control is another consideration. Different grasses attract different pests. St. Augustine is prone to chinch bugs and sod webworms. Bermuda can get armyworms and grubs. Monitor your lawn regularly for signs of damage. Early detection makes treatment easier and more effective.
Weeds are also a challenge. A dense, healthy lawn naturally suppresses weeds. If your lawn is thin or stressed, weeds will move in. Keep your grass thick and vigorous. This is the best defense against weed invasions. Mow high, water deeply, and fertilize properly.
Seasonal care is important too. In the spring, clean up dead material and apply a pre-emergent herbicide. In the summer, focus on watering and mowing. In the fall, reduce fertilizer and prepare for dormancy. In the winter, keep foot traffic off the dormant grass.
You might be tempted to mix grasses to get the best of both worlds. But in reality, you get the worst of both. The different needs and growth habits create constant conflict. It is better to have one grass that is perfectly suited to your yard than two that are always fighting.
Talk to your local extension office or a lawn care professional. They can give you specific advice for your area. They know which grasses grow best in your climate and soil. Use their knowledge to make an informed decision. It is a small step that can make a big difference.
In the end, a beautiful lawn comes from proper care and the right grass choice. Dont overcomplicate it. Choose one grass, give it what it needs, and it will reward you with a lush, green carpet. Avoid the temptation to mix. Your lawn will thank you for it.
So if you are thinking about mixing bermuda grass with st augustine grass, think again. The effort is not worth the result. Stick with a single species and focus on doing it well. You will have a healthier, better-looking lawn with less work. That is a win-win situation for any homeowner.