Centipede grass is a warm-season turfgrass, prone to excessive thatch buildup as result of over-management and slow-decaying thatch matter. It’s ideal for lawnowners with little time to care and maintain them. It is aggressive, dense, attractive and weed-free. However, thatches buildup make unsightly centipede lawns.
Dethatching centipede grass lowers its vulnerability to extreme temperatures, drought, and diseases. However, it should be done with caution, as aggressive dethatching tools can cause excessive turf injury or even die back. Dethatching centipede grass is best done by hand/power rake, vertical lawnmower, and biological dethatching liquid.
Here’s how to manage thatch to make your centipede grass lawn the best version of itself.
Table of Contents
Should you dethatch centipede grass?
Centipede grass thatch consists of dead shoots/stolons, shed roots, and other organic matter on the lawn. You should dethatch centipede grass since thatch makes lawn soil more acidic, which is detrimental to the growth of centipede grass. Thick layers of thatch also form a barrier that prevents fertilizer and herbicides from reaching the soil below.
Another reason why you should get rid of thatch in centipede grass is that new grass forms roots in the thick thatch layer rather than the soil. Such shallow-rooted grass is more vulnerable to heat, cold, and drought conditions. Finally, thick thatch forms a great habitat for disease-causing insects and microbes.
Note: Studies have also shown that thatch buildup in centipede turfs causes ‘centipede decline’, a condition whereby centipede grass fails to green up in the spring.
Centipede grass readily forms thatch from its dead stolons, leading to thick thatch buildup. Stolons are the above-ground runners through which centipede grass spreads. The high lignin content in the stolons doesn’t allow thatch to break down easily. Therefore, they form a thatch layer between the centipede lawn and the soil.
Centipede grass doesn’t need as much fertilizer as other types of turf grasses – hence the name ‘Lazy man’s grass. It only needs two pounds of nitrogen per 1000 square feet annually. Over-fertilization makes it form thatch. Overwatering the lawn and letting the grass grow taller than two inches before mowing also encourages excessive thatch buildup on centipede turfs.
Reasons why you should dethatch centipede grass
Centipede grass thatch accumulation poses challenges that impact its vitality and overall health:
- Hinders root growth– results in shallow, stunted roots, diminishing the grass’s ability to access essential nutrients.
- Excessive thatch is a breeding ground for fungal diseases like brown patches, thriving in moist conditions.
- Reduced cold tolerance and uneven growth further compromise the grass’s resilience.
- Additional consequences include scalping during mowing, decreased nutrient efficacy, drought intolerance, and weakened turf integrity.
Note: Strategic thatch management through regular dethatching, timely aeration, and precise fertilization is vital for safeguarding centipede grass and preventing associated issues.
How do you get rid of thatch in centipede grass?
Dethatching is best done when the soil is moist. As such, irrigate it 2 days before dethatching to prep your centipede lawn for dethatching. Then, use a hand leaf rake, a power rake, a vertical lawn mower (verticutter), or a dethatching liquid to effectively eliminate thatch in centipede grass.
Use a hand leaf rake
The simplest way to get rid of excessive thatch buildup on centipede grass is by vigorously raking the lawn using a hand leaf rake. The rake’s tines will pull out the thatch from below the grass blades to the top of the lawn. Note that hand rakes are less invasive than power dethatching tools like power rakes and vertical mowers and are thus less likely to cause excess turf injury.
Once done, transfer all the dead matter that you’ve raked off the soil surface to your compost pile. Once the thatch is fully decomposed, it becomes a great source of nutrients for centipede grass.
Note: Dethatching using a hand rake is best reserved for when you have a small lawn and the light thatch buildup. Trying to dethatch an expansive centipede lawn with heavy thatch buildup using a hand leaf rake is tiresome. Power dethatching tools come in handy in bigger fields with heavy thatch buildup.
Use a power rake
A power rake is a more effective alternative to a hand rake. To use a power rake to dethatch your centipede lawn, adjust the vertical tines to a depth of 0.5 inches and space them three inches apart.
Run the power rake in a single direction. Multidirectional passes may cause severe turf injury that may kill your centipede grass. You don’t have to get rid of all the thatch, as this increases the amount of stolon injury. The goal is to create as many air and moisture pockets while preserving your centipede turf’s health.
Note: The spring-loaded tines penetrate the thatch and tear out some of it before dropping the dead vegetation on the surface of the lawn.
Use a vertical lawn mower
You can also use a vertical mower or a verticutter to dethatch centipede grass. The vertical blades pull up the dead vegetation to the surface, thus helping to keep the grass healthy. Attaching a collecting bag to your vertical mower helps. You won’t have to manually collect the thatch you’ve pulled out.
Space the blades three inches apart. The spacing ensures that you don’t cause extensive damage to the stolons, as centipede grass doesn’t have underground runners (rhizomes) and may not be able to recover from excessive vertical mowing.
Note: Immediately irrigate the lawn once you’re done verticutting to keep any exposed roots from drying out.
For warm-season turfgrasses like centipede grass, verticutting is best done in early spring, just as the turf is about to green up. You should also fertilize the lawn with a quick-release nitrogen fertilizer one week after vertical mowing for faster turfgrass recovery from physical injury.
Use biological dethatching liquid
Unlike the other dethatching tools, dethatching liquids is a relatively new concept. One advantage they have over aggressive dethatching tools is that they don’t physically damage the centipede grass since they don’t cut through stolons.
Dethatching liquids contain carbonic enzymes and microbes that speed up the decomposition rate of centipede thatch. Most commercial dethatching liquid products are meant to be diluted with water and sprayed onto the lawn. Some of these products contain additional fertilizer ingredients for added value.
Note: You can also make your own dethatching liquid at home using readily available household products like soap.
When is the best time to dethatch centipede grass?
The best time to dethatch centipede grass is when the thatch buildup is 0.5 inches high or more. To determine the height of the thatch, cut out a small triangular section of turf using a shovel and pull it out. Then, measure the depth of the thatch, starting from the base of the grass blades to the top of the soil. If the thatch is higher than 0.5 inches, it’s time to bring out your rake.
Dethatch centipede grass in the late spring-early summer to allow quicker recovery from physical injury after dethatching. It’s best to dethatch centipede grass when it is actively growing and temperatures are warm
Avoid dethatching during the dormant winter months or during the peak heat of summer, as the grass may struggle to recover during extreme conditions
See Also: When should you dethatch your lawn?
How often to dethatch centipede grass
The frequency at which you dethatch your centipede lawn should be determined by how fast thatch buildup occurs. When the thatch layer exceeds 0.5 inches high, it’s time to dethatch again. Overwatering or over-fertilization leads to faster thatch buildup on your lawn. You’ll need to dethatch more often if you overwater or overfertilize the lawn.
How high/low should centipede grass be cut?
You should mow Centipede grass at a height of 1-2 inches. This ensures you don’t get rid of more than 1/3 of the length of the grass blades, thus leaving enough behind blade surface area for photosynthesis.
Centipede grass that’s longer than 2.5 inches is more vulnerable to thatch buildup. Therefore, cut your centipede turf back to 2 inches every time it grows past 2.5 inches.
Note: Use sharp blades when mowing centipede grass. Dull blades yellow the raggedly-cut edges and increase the turf’s vulnerability to disease.
Tips for dethatching grass
- Mark out sprinkler heads before using a power dethatching tool on your lawn to avoid damaging them and cutting through irrigation lines that are buried close to the surface.
- If you’re renting a power dethatcher, ask the owner to adjust the tines or blades to cut no more than 0.5 inches into the soil. Also, the tines should be spaced at least 3 inches apart. Ask for a demonstration or an instruction manual if you’re unsure of how to use the machine.
- Water and fertilize the grass after dethatching to encourage faster recovery from physical injury caused by the dethatching tools.
What causes thatch in centipede grass?
Excessive growth as a result of high nitrogen fertilization, adequate rainfall, and favorable warm-humid climate. Organic matter from grass clippings left on lawns after mowing to decompose can lead to thatch accumulation. Depleted microbial life, compacted soil reduces the natural decomposition of thatches which gets worse when coupled with improper watering, fungal diseases and insect problems. These are the main causes of thatch buildup in centipedegrass lawn.
What grass will choke out centipede?
Bermudagrass, Zoysia, St. Augustine, tall fescue, crabgrass, nutsedge, and goosegrass can choke out centipede grass lawns. These grasses are more aggressive with deep roots features/ characteristics that can hinder centipede growth and establishment. They establish to form a more dense mat-like cover. Crabgrass is an annual weed, while Nutsedge is an invasive perennial weed that spreads through tubers in the soil.
Should centipede grass be aerated?
Yes, heavily compacted and poorly drained soil restricts proper decomposition of organic matter. Aerating centipedegrass lawn is recommended for optimal turf health ( improves water, nutrients, and oxygen penetration to the roots) and to help prevent thatch buildup.
In addition, when overseeding or plugging centipedegrass, aerating helps to create holes for better seed-to-soil contact and root establishment.
When should you dethatch centipede grass?
Dethatching centipedegrass in late spring to early summer when it is actively growing and temperatures are warm. Ensure the Centipedegrass is not also dealing with drought, heat stress, disease, or insect issues to avoid adding more stress which results in quicker turf recovery.
Avoid dethatch immediately before or after aeration since it may compound stress. Ideally, separate Aeration and dethatching by 4-6 weeks.
What is thatch buildup?
This layer of accumulated dead plant material (centipede grass stems, stolons and roots) at the soil surface.
i. Clemson University, Home & Garden Information Center: Centipede Grass Yearly Maintenance Program
ii. University of Georgia- Cooperative Extension: Centipede Grass Decline