A thin Bermuda grass lawn is usually caused by too much shade, compacted soil, poor drainage, and lack of nutrients. If your lawn is not growing tall and spreading to fill in the bare spots, changing your care practices can make it thicken up. So, how do you make Bermuda grass thicker and greener?
Mow your lawn slightly below 1 inch every 5-7 days to encourage lateral growth and make Bermuda grass grow thicker. Also, water the lawn with 1 inch of water per week and fertilize with a 16-4-8 NPK fertilizer containing iron to thicken and green-up a thin Bermuda grass lawn.
While you can use a combination product containing fertilizer, seed, and soil improver such as Scotts Turf Builder Thick’R Lawn to get a thicker lawn, there’s a lot more to do to improve your lawn. I’ve explained below the simple steps and tricks to help you thicken and green up your bermudagrass lawn quickly.
How to Make Bermuda Grass Thicker
The best way to make Bermuda grass thicker is to feed the lawn with slow-release nitrogen fertilizer such as Milorganite, then water it once per week to improve its growth rate. Also, mowing slightly lower will improve lateral growth and make the lawn thicker and fuller.
Here are 8 steps to make Bermuda grass grow thicker and fuller:
1. Mow lower more frequently
Set your lawn mower lower slightly lower than 1.5 inches when mowing Bermuda grass to discourage vertical growth and encourage more lateral growth. Increased lateral growth of grass stolons helps fill in the bare spots, making your lawn grow thicker and fuller quickly.
Bermuda grass is an aggressive turfgrass and can grow to 4-12 inches tall if not mowed. However, you want to make it grow and spread nicely to form a dense carpet. Therefore, push it to grow more laterally than vertically.
Pro tip: Be careful not to mow too low and risk scalping and damaging your lawn. The recommended mowing height for Bermuda grass is 1-1.5’’ so set the mower anywhere between 0.5 and 1 inch low when you’re going for a fuller lawn.
Other tips for making your Bermuda lawn grow thicker by mowing include:
- Use a reel mower for bermudagrass for a much cleaner cut. I use and recommend the Fiskars StaySharp Reel Mower for this.
- Keep your mower’s blades sharp to prevent hacking the grass blades and exposing the turf to disease.
- Mow every 5 to 7 days and less often when the lawn is drought-stressed.
If you’re feeding your lawn properly and mowing as I’ve recommended above, your turf will soon fill in and become thicker and fuller quite fast.
2. Overseed to fill in the thin and bare spots
Overseed a thin bermuda grass lawn to fill in the bare spots and areas where the turf is thin. The best time to spread grass seed over an existing lawn is in the fall to restore the its thickness during the active growing season of spring.
Overseeding bermuda grass is a great way to get it to thicken up and remain green throughout the season. I recommend overseeding with a cool-season turfgrass if your lawn turns bare and brown during the cold months of winter when Bermuda grass goes dormant.
Alternatively, you can overseed with Bermuda grass seed to thicken up your lawn if you don’t mind waiting out the dormancy period and start enjoying a greener lawn in the spring.
Here are great overseeding tips to help you improve your lawn:
- Apply pre-emergent herbicide to kill weeds 45 to 90 days before overseeding. If you apply a weed killer too soon before reseeding can prevent seed from germinating.
- Overseed at a rate of about 8 lbs of ryegrass seeds per 1000 square feet of lawn area for fuller, thicker growth.
Good grass to overseed bermuda grass with are perennial ryegrass and annual ryegrass. You want to avoid overseeding with cool-season turfgrass varieties that last long into the warm season such as tall fescue and Kentucky bluegrass.
3. Feed a Bermuda grass a nitrogen fertilizer
When Bermuda grass is not growing tall or spreading, the problem is likely lack of fertilizer. Feeding your lawn with nitrogen is key to reviving it from dormancy and helping it grow thicker and fuller.
Apply a 16-4-8 NPK fertilizer such as the Andersons Professional PGF Complete Fertilizer in the spring when the grass is actively growing and spreading to push it to grow thick faster. If the lawn is very thin, apply 1.0-1.5 lbs of Nitrogen per 1000 square feet per month to encourage faster growth and thickening.
Another best fertilizer to thicken Bermuda grass and make it spread is Milorganite. It is a slow-release fertilizer that can feed the lawn all season long with just 1 or 2 applications. You can also use a general-purpose 4:1:2 NPK fertilizer to help Bermuda grass thicken faster.
Fertilizer feeds your soil with the necessary nutrients that the grass will need to stay healthy and fight off diseases. It also promotes drought resistance, with drought being a major cause of a patchy turfgrass appearance.
I would advise that you test your soil nutrient levels first before applying nitrogen fertilizer to determine the deficient nutrient that’s causing a sparse lawn. Applying excess fertilizer (salts) to the soil can cause your grass to burn and turn yellow or brown.
4. Water the lawn once per week
Drought stress often leads to a thin bermudagrass lawn. If your lawn is not getting at least 1 inch of water every week during the spring-summer period, it will experience slow growth and poor spreading.
To get Bermuda grass to thicken, water with at least 1 inch of water per week to enhance root development and lateral growth of grass stolons. Proper irrigation promotes deeper root growth, improved nutrient absorption, and ultimately, a dense Bermuda grass turf.
Here are my important watering tips for getting Bermuda grass to thicken:
- During the summer months, increase the watering to more than 1’’ per week to counter drought stress.
- If your turf is established on sandy soil, provide 0.5” of water at a time 3-4 days apart as the soil does not hold water for long.
- If the grass is growing in clay soils, water for shorter periods but more frequently to allow the water time to get absorbed into the root zone.
Ideally, water once a week for a long period, as opposed to watering frequently/daily for shorter periods. Such infrequent and sustained irrigation triggers deeper root growth that can draw in more nutrients for a healthier, thicker lawn.
When watering your Bermuda lawn, you should continue until you’ve soaked about 1/4-inch of the soil. Avoid overwatering your lawn, as this will kill your Bermuda grass or make it lose its green color. Use a rain gauge to measure how much irrigation you’ve done when using a manual lawn sprinkler.
5. Improve soil quality and pH to 5.8-7.0
Stunted growth and general ill-health of your bermudagrass turf is a sign of poor soil quality. I’ve found pH problems to be a major cause of weak and poorly-developed lawns. You can determine if improper soil pH is the cause of a thin turf by doing a soil pH test. Your local extension office can help with this.
Bermuda grass grows thick and healthy when the soil pH is between 5.8 and 7.0 and can easily tolerate more alkaline conditions. If the pH is too acidic, nutrient availability becomes limited and the grass will thin out and grow poorly.
Apply lime to the lawn on a regular basis to neutralize the acidity of the soil and fix the pH back to a range between 5.8 and 7.0. The grass will be able to take up nutrients effectively and grow thicker and fuller.
Apart from pH, the type of soil can also be the reason for a thin lawn. Although Bermuda grass can grow in clay soils due to its well-adapted rhizomes and fibrous roots, it spreads best in well-draining soils.
You want to make sure the soil is well-aerated, contains lots of organic matter, and allows for proper drainage. Therefore, amend the soil in your yard to help the grass grow into a dense carpet.
Apply topsoil or organic manure in the lawn before planting Bermuda grass seed to provide a rich medium for the roots to grow into. If the soil is too clumpy, mix a little sand or manure to loosen it up and encourage the grass to grow thick and spread faster to cover bare spots.
You can also improve clay soil tilth by mulching, as it helps with moisture and nutrient retention. I’d recommend mulching with chop-and-drop nutrient accumulators. These are plants whose roots usually accumulate important soil nutrients. Therefore, when cut back and applied as a mulch, they significantly enrich the soil, consequently facilitating thicker turfgrass growth and spread.
Another alternative to mulching is the application of topsoil. Commercial topsoil is usually fed with various nutrients that enrich it, making it suitable for use on lawns with poor-quality soil.
6. Control weeds early in the spring
Weeds compete for nutrients and space, leaving your lawn appearing thin and patchy. Some weeds such as crabgrass and clumping tall fescue are aggressive and can choke out turfgrass. It can be difficult to get Bermuda grass to grow thick and full with a heavy infestation of weeds.
Apply a pre-emergent herbicide in the spring
It is important to apply a pre-emergent early in the spring just when Bermuda grass gets out of dormancy to prevent weeds such as crabgrass from germinating in the lawn.
The most common annual grassy weeds re-emerge at a certain time every year. If you wait to kill them off after they’ve germinated, there’s a chance they will have already caused some damage by choking young Bermuda grass.
Weed preventers or pre-emergent herbicide is the backbone of every season’s weed control effort. It is important to apply these herbicides at the right time to prevent all kinds of weeds from germinating and competing with your turfgrass. See this guide on when to apply crabgrass preventer for more details.
Kill weeds with post-emergent herbicides
Depending on the time of the season, you might want to use a post-emergent herbicide to kill existing weeds to allow Bermuda grass to grow thick and full. For example, you can apply a crabgrass killer on actively-growing crabgrass weeds to get rid of them in the lawn.
Some tips worth considering include the following:
- If killing weeds leaves bare patches in your lawn, overseed or plant new sod to fill in the bare spots.
- Always apply herbicides that are safe for Bermuda grass lawns. Some weed killers can also stun the turfgrass and cause discoloration, stunted growth, or even kill some of the grass.
Since these weeds compete for limited soil nutrients with your Bermuda grass, eliminating them is one of the most effective ways of achieving a healthier, greener, and thicker Bermuda grass lawn. You’ll want to apply a weed-killer herbicide before the warm growth seasons, as doing so will have a negative impact on your Bermuda grass as well.
7. Dethatch during the growing season
Dethatching is good for a Bermuda grass lawn if it is done during the active growing season; and only when the thatch is more than 1/2 inch thick. If you dethatch when Bermuda grass is dormant, it can easily kill the lawn or leave it thin and sparse.
I’d recommend that you overseed your bermudagrass lawn to get it to thicken up faster if you dethatched with a power rake during the slow-growing or dormant season.
While overseeding a bermudagrass lawn is best done in September or in the fall, you can do it early in the spring as soon as the grass gets out of dormancy. This will help fill in the bare and thin spots that were caused by heavy dethatching during dormancy.
8. Aerate your lawn
Soil compaction prevents roots from growing deep enough to draw nutrients and water from the soil. If not corrected through core aeration, it can lead to a weakened turf that’s prone to weeds, pests, and disease infestations.
Aerate your lawn once every season in the spring to help Bermuda grass get thicker and develop into a dense turf. Aeration and dethatching are important for stronger roots and enhanced drought resistance.
Aeration allows for a better flow of air, nutrients, and water into the Bermuda grass roots. The process entails perforating the soil by removing plugs of soil for deeper root growth that can facilitate vigorous turfgrass growth. Lawn aeration works to improve general lawn quality as it reverses the effects of soil compaction and poor drainage.
Pro tip: The best time to aerate your Bermuda lawn is in late spring or early summer when the turfgrass is actively growing, as the grass plants will have more stored energy. Aerating a newly planted lawn can cause irreversible damage to young shoots while aerating just after the dormant seasons leaves the soil exposed to weed seeds.
9. Improve sunlight in the lawn
Bermuda grass established in a shaded area will appear thin and patchy. When establishing your lawn by sodding or seeding, ensure that the lawn area is not completely obstructed from sunlight access. Bermuda grass has poor shade tolerance, and as such it requires at least 7 hours of sunlight exposure every day to grow thicker and greener.
Here are tips to improve sunlight exposure in your lawn:
- Prune trees around the yard to reduce the canopy above your lawn for better sunlight penetration.
- Establish your lawn away from the shade of tall buildings. Allow the grass to receive at least 7 hours of morning sunlight.
- For a smaller lawn, install a sunlight reflector in the yard to increase the hours your lawn receives sunlight.
If improving sunlight exposure is not an option for your lawn, you might want to consider planting a more shade-tolerant turfgrass such as centipede grass, or even some types of St. Augustine grass such as Floratam and Palmetto.
Ways to Make Bermuda Grass Greener
Most Bermuda grass lawns are light green in color and any signs of discoloration could mean something is wrong with your lawn. If you follow a good Bermuda grass maintenance calendar, you’ll get a lush green, dense lawn that feels like a carpet under the feet. However, if the lawn appears unhealthy, there are a few things you can do to make it turn green again.
Here’s how to make Bermuda grass greener:
Apply an iron supplement
If you water your bermudagrass turf every week but it still appears yellowish instead of green, it is likely that the turf is nutrient deficient. Yellowing of grass blades is also called chlorosis and can be corrected with an iron supplement.
Apply an iron supplement such as Ironite to help Bermuda grass grow greener. Iron is a color-enhancing nutrient for lawns. It aids in the formation of chlorophyll – the green pigment in the leaves of plants.
Note that Ironite does not work as a fertilizer, so you’ll still need to feed your lawn with a well-balanced fertilizer to push Bermuda grass to grow thicker. You can, however apply a 2-in-1 fertilizer such as Milorganite to feed and green up Bermuda grass quickly.
Feed with a nitrogen fertilizer
Nitrogen is a crucial nutrient that helps regulate water and nutrient uptake. Lack of nitrogen not only leaves the lawn thin and poorly developed but also makes it lose its color.
- Apply 1 lb of nitrogen per 1000 square feet of lawn to encourage the grass to grow thicker and greener.
- Use an organic slow-release fertilizer to constantly feed your grass over 8-10 weeks to help the lawn thicken and green up throughout the growing season.
Pro tip: While there are some fertilizers specifically great for bermudagrass, I’d advice that you start with a soil test to determine the deficient nutrient. This will guide you choose the best fertilizer for your Bermuda grass lawn.
- Charles Peacock, Professor, and Extension Turfgrass Specialist, Crop and Soil Sciences, NC State Extension: Carolina Lawns: A Guide to Maintaining Quality Turf in the Landscape
- T. Koski and V. Skinner, Colorado State Extension: Lawn Care Tips for Thicker Turfgrass
- Dr. Leonard Perry, Horticulture Professor Emeritus, University of Vermont: Understanding Lawn Thatch