You may have heard dethatching is good for your lawn, but what is dethatching? Dethatching means getting rid of the dead and living organic material (thatch) that builds up between the soil surface and your lawn.
Learn more about dethatching, the benefits, and when and how to do it.
What does dethatching mean?
Dethatching involves removing the dense layer of thatch—made up of dead grass, roots, and other organic material — that accumulates between the soil and your lawn. When this layer grows thicker than ½ inch in warm-season grasses or ⅓ inch in cool-season grasses, it prevents air, nutrients, sunlight, and water from reaching the soil and roots.
Excess thatch can happen for many reasons, including:
- Overwatering or frequent watering
- Too much nitrogen fertilizer that promotes excessive growth and a rapid buildup of organic matter
- The absence of microorganisms (to break down organic matter) as a result of pesticides
- Compacted soil due to foot traffic, home improvement activities, and not enough lawn aeration
- Nutrient-poor soil with a high clay or sand content
- Acidic soil with low beneficial microbe levels
- Removing more than one-third of your grass as a result of infrequent mowing
- Leaving excessive grass clippings on the lawn without proper mulching
How do you know your lawn is due for a powerful, deep raking? It may display signs such as:
- Grass that is spongy and springy to the touch
- Grass blades that are weak, thin, or dull
- Weeds that grow in the grass
- Runoff that happens when the soil isn’t absorbing much water
- Minimal grass growth
Benefits of dethatching
Dethatching offers several benefits for the health and visual appeal of your lawn:
- Better airflow: Removing thatch allows air to reach the soil and roots more effectively, promoting healthier grass or plant growth.
- Better water absorption: Dethatching helps water penetrate the soil more easily, contributing to proper root moisture levels and reducing standing water and runoff.
- Enhanced nutrient uptake: Eliminating thatch helps fertilizer nutrients get to the roots faster, leading to a stronger and more radiant lawn.
- Increased curb appeal: A thatch-free lawn looks more lush, vibrant, and eye-catching.
- Stronger roots: Without thatch, grassroots can grow deeper and stronger, making your lawn more resilient to drought, weeds, fungal diseases, and pests.
- Less soil compaction: When combined with aeration, dethatching helps reduce soil compaction and improve lawn health.
When to dethatch
When you dethatch your lawn depends on your grass type.
Dethatch your cool-season grass (typical in the northern parts of the U.S.) in early spring or late summer to early fall, during the grass’ active growing season.
Dethatch your warm-season grass in late spring to early summer, also during its vigorous growth stage. You’ll find warm-season grasses in the southern parts of the U.S. or in the Transition Zone (the USDA hardiness zone map can help you determine which grasses and plants thrive in your location).
Always avoid dethatching when your lawn is dormant or stressed. Don’t dethatch in the peak of summer heat or during a drought, as this can severely damage your lawn.
How to dethatch
How you dethatch depends on which tool you choose. The main equipment for dethatching includes:
- Manual dethatcher
- Electric dethatcher
- Power rake
- Vertical mower
- Tow-behind dethatcher
You can buy or rent dethatching equipment based on:
- Your budget
- How often you want to use the tool(s)
- The storage space you have
- The maintenance skills or time you have
Your local garden center or home improvement store will carry the various tools mentioned and offer rental services. Professional dethatching services range from $145 to $247.
No matter the method, you’ll want to mow your grass a bit lower than normal (to about half its regular height) before dethatching. This allows easier access to the thatch layer, puts less stress on the grass, as the mower blades can focus on the thatch rather than damaging the longer grass blades, and ensures effective thatch removal.
You’ll also want to water your lawn lightly a day before to make it easier for the tools to penetrate and lift the thatch.
After dethatching:
- Rake up the debris. For an eco-friendly approach, try backyard composting instead of disposal.
- Aerate the lawn to improve soil structure. This is a good time to overseed your lawn and fill in bare patches (if any).
- Since dethatching isn’t the gentlest process, apply fertilizer and water your lawn to help existing grass recover and new grass grow strong.
Dethatching with a manual dethatcher
Best for: Small lawns with a mild thatch problem (one-half to an inch of thatch buildup).
Manual dethatchers (also known as thatch rakes) have short, curved blades designed to slash into your thatch and pull it up. They’re the least expensive dethatching option but also the most labor-intensive. Manual dethatchers have different blade angle settings, so you can choose how deeply the rake penetrates your lawn (depending on the depth of your thatch).
How to use:
- Put on protective gear: gloves, safety glasses, and long-sleeved clothing.
- Like using a normal rake, apply firm pressure to ensure proper thatch penetration.
- Move the rake across the lawn in a back-and-forth motion.
- Pull upward to loosen and remove thatch.
- Collect the thatch.
DIY tool options:
- 12.8inch Wide Dethatcher Rake for Cleaning Dead Grass
- 54 in. Hardwood Handle 19-Tine Adjustable Thatch Rake
Rental cost: Approximately $35
Dethatching with an electric dethatcher
Best for: Medium-sized lawns with a mild to medium thatch problem.
Electric dethatchers look like miniature lawn mowers, with spiny rotating tines that you can set to different levels.
How to use:
- Wear protective gear: gloves, safety glasses, and long-sleeved clothing.
- Refer to the instruction manual to set the electric dethatcher to the appropriate depth setting for your lawn. You’ll want to start with a shallow setting and test out a small area, adjusting the depth gradually to grab more thatch.
- Like a lawn mower, make two to three passes across your yard in different directions. This method will make your lawn look like a grassy checkerboard.
- Collect the thatch.
DIY tool options:
Rental cost: Approximately $75 to $80
Dethatching with a power rake
Best for: Larger areas with a severe thatch problem and dense grass that can withstand tougher treatment.
Power rakes are similar to lawn mowers. They have steel, knife-like tines (flail blades) on the underside that rotate perpendicular to the ground.
How to use:
- Wear protective gear: gloves, safety glasses, and long-sleeved clothing.
- Make two or three passes (perpendicular to each other) across your lawn to dethatch the area thoroughly. Do this in straight lines, overlapping each pass slightly.
- On your first pass, set the blades at the highest level to prevent accidental damage to your lawn as you learn to use it.
- It’s important not to scalp your grass and tear out the roots as you go.
- Collect the thatch.
DIY tool options:
- Mellif 14.2” Cordless Dethatcher
- Einhell GC-SC Power-X-Change 36-Volt Cordless 12-Inch Scarifier and Dethatcher
Rental cost: Approximately $80
Dethatching with a vertical mower
Best for: Large lawns with a severe thatch problem that could benefit from overseeding.
Vertical mowers (also known as verticutters) have flat, vertical discs that slice down through the thatch and soil, creating grooves. They dig deep, uprooting thatch to give roots an extra dose of air, water, and nutrients from the soil surface. This is also called verticutting.
How to use:
- Wear protective gear: gloves, safety glasses, and long-sleeved clothing.
- Set the blades to the proper spacing (2 inches or more) and depth (based on your thatch level).
- Turn on the verticutter and move it across the lawn in straight lines, much like mowing. Overlap each pass slightly for even coverage and switch directions for added aeration.
- Collect the thatch.
DIY tool options:
Rental cost: Approximately $110
Dethatching with a tow-behind dethatcher
Best for: Medium to large lawns with a severe thatch problem.
A tow-behind dethatcher is an attachment for lawn tractors or riding mowers that makes it easier to dethatch larger areas. It features tines or blades that penetrate the soil and pull up thatch from the lawn as it moves across the surface.
How to use:
- Wear protective gear: gloves, safety glasses, and long-sleeved clothing.
- Attach the dethatcher to your riding mower or lawn tractor, following the manufacturer’s instructions.
- Set the tines to the appropriate depth (around ½ inch deep) to effectively reach and remove the thatch.
- Drive your mower or tractor across the lawn in straight lines, overlapping them slightly to ensure even coverage. Maintain a consistent speed to reach all areas.
- Once in a while, stop and check the tines for accumulated debris. If it’s substantial, clear it before continuing.
DIY tool options:
Rental cost: Approximately $40 to 350
How to prevent thatch
Dethatching is a sweaty, muscle-heavy chore that takes up precious time. Fortunately, with the right lawn care practices, you may never need to dethatch again.
- Avoid frequent, shallow watering. Instead, water your lawn deeply two to three times a week (to a total of 1 to 1.5 inches of water), depending on your grass type. The best time to water your grass is between 5 a.m. and 9 a.m. when evaporation and wind are less likely.
- Test your soil every three to five years. Check with your cooperative extension service about local labs that can analyze it.
- Avoid overfertilizing, especially with nitrogen-rich fertilizers. Fertilize according to your soil’s needs (see your soil test report), grass type, weather conditions, and lawn use (high-traffic areas may require more frequent feedings to recover from frequent use).
- Stay away from chemicals that harm earthworms in your yard. Some pesticides and fungicides can severely damage the earthworm population, reducing the breakdown of organic matter and leading to excessive thatch.
- Mow your lawn regularly, following the one-third rule. At each mow, cut your grass no shorter than one-third of its height. This reduces stress on the grass, prevents root growth and photosynthesis problems, and reduces the amount of grass clippings.
FAQ about dethatching
Which grasses are more susceptible to thatch buildup?
Your lawn’s susceptibility to thatch also depends on your grass species.
- Cool-season grasses: Perennial ryegrass and tall fescue lawns don’t typically have a thatch problem. Kentucky bluegrass, creeping red fescue, and creeping bentgrass lawns develop more thatch due to their dense, aggressive rhizome and stolon growth.
- Warm-season grasses: Zoysia and Bermudagrass produce abundant roots, rhizomes, and stolons, making thatch management more difficult.
Are there any benefits to thatch?
Thatch isn’t always bad; a thin layer (less than half an inch thick) is healthy for your grass.
Here are the benefits of thatch in moderation:
- Thatch acts as a natural mulch, keeping your soil moist and providing insulation during extreme temperature fluctuations.
- A little thatch gives you traction when you’re walking or running and softens the impact of your feet on the soil. Lawns with a bit of thatch won’t get compacted as easily as thatch-free lawns.
- Thatch improves soil quality by acting as a food source for beneficial bacteria.
- Thatch keeps a steady soil pH, which measures the acidity and alkalinity in your soil. A moderate pH level supplies your turfgrass with the nutrients it needs.
- Thatch naturally filters rainwater, straining out contaminants for cleaner groundwater and aquifers.
Can dethatching damage my lawn?
Dethatching can temporarily stress your lawn, but it promotes long-term grass health. To reduce potential damage, dethatch according to your grass type, avoid cutting deep cuts, and follow up with good lawn care practices.
Let a pro dethatch your lawn
Dethatching can directly impact the health of your grass, but it requires time and effort on your part. To achieve a standout lawn, you’ll have to couple dethatching with healthy lawn care practices.
If your thatch problem is extensive or you have a large yard, consider hiring a local lawn care expert. Let them save you time, effort, and expense on dethatching equipment to rejuvenate your lawn and ensure its long-term health.
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