Thatch is the interwoven layer of organic matter consisting of dead and decomposing plant stems, rhizomes, stolons, and roots lying between grass blades and the soil surface; excessive thatch harbors disease-causing fungi and pests, and it is detrimental to your lawn health.

Lawn dethatching is mechanically removing the excess thatch layer from your lawn so the soil can receive enough air, water, and nutrients, which stimulates the growth of your turfgrass roots.

When and how often you dethatch your lawn depends on your grass type and soil composition. There are different types of lawn grasses, and they produce thatch at different rates.

what is dethatching

Knowing when to dethatch your lawn isn’t difficult if you know what to look out for. Healthy lawns have a thatch thickness of fewer than 0.5 inches, so no harm there. But yards with more than an inch thick thatch will feel spongy or bouncy underfoot. Other telltale signs of a lawn with excessive thatch include unhealthily thin, pale-looking grass and excessive water runoff, i.e., your yard has a low water absorption rate. It is imperative to check the lawn’s thatch level and measure its thickness before you dethatch. To do this, kneel on your lawn to inspect the layer of thatch beneath the grass. Thatch is a grayish brown colored, tightly interwoven matting of decayed and old grass blades, stems, clippings, and runners.

It may look disgusting to some, but it’s harmless to touch. Thrust your finger into the grass and push down on the thatch layer to feel it’s thickness. If you think you can still push down into the thatch, your lawn has excessive thatch.

Measuring the thickness of the thatch layer is a relatively straightforward process. Insert a garden trowel into the ground, dig up a small section of your lawn, and measure the thatch thickness with a ruler. If the thatch thickness exceeds ½ inch (1cm), then you’re good to dethatch.

How to dethatch your lawns

Homeowners can detach with a simple dethatching rake or hire a landscaping professional who may use a power rake or an industrial-grade dethatcher to perform the procedure. Dethatching can wreak havoc on your turfgrass and leave your lawn looking worse for wear. How quickly your turf recovers after the dethatching depends on your experience and patience in implementing lawn improvement practices to help your grass recover soon.

Below is a list of dethatching methods:

Dethatching rake

A dethatching rake is a handheld thatch remover with sharp, metal blades designed to remove thin layers of thatch on small lawns. A dethatching rake works similarly to an ordinary leaf rake. To operate, push the rake into your yard to penetrate deep into the thatch, then pull out to remove the thatch from the soil. A dethatching rake is available at hardware and gardening stores.

dethatching hand rake

Power rake

Power rakes are mechanical dethatching devices resembling lawnmowers but fitted with rotating metal tines that dig into the lawn to pull up thatch from the soil surface. Power rakes are more effective on lawns with a thin layer of thatching and can be used for aggressive thatch control on lawns with emerging thatch issues. You can rent power rakes from your local equipment rental store.

power rake for dethatching

Vertical mower

Vertical mowers, also known as verticutters, are machines equipped with adjustable revolving blades that slice through the thatch layer to remove thatch from the soil surface. Landscaping pros prefer vertical mowers because they are super-efficient at extracting thick layers of accumulated thatch on largely neglected lawns in need of restoration. You can rent a vertical mower from most garden equipment rentals, and they are bulky machines that will require a truck and some help from your friends to move and unload. It’s actually more practical to hire a professional to detach your lawn with a vertical mower than doing it yourself. Please ask the rental company for operating guidance when hiring a vertical mower, and be sure to follow the instructions carefully.

Below is a list of helpful tips to help you dethatch your lawn successfully.

  • If you’re hiring a vertical mower, ask the rental company to set the revolving blade spacing and cutting depth to your thatch thickness and grass type.
  • Detaching a soaked or dry lawn will damage your soil. Water your lawn intermittently for a couple of days to keep the soil moist before you dethatch.
  • Mark sprinkler heads, irrigation lines, and other objects on your lawn before dethatching with the vertical mower.
  • When dethatching with a vertical mower, let the direction of your second pass across the lawn be perpendicular to the direction of the first run.
  • You can rake and recycle the thatch back into your lawn as mulch.
  • Fertilizing your lawn after dethatching will help your lawn recover faster. Do not fertilize before dethatching.

How often should I dethatch?

You can dethatch your lawn annually or when the thatch exceeds ½ inch thickness depending on the grass type and local growing conditions. Extremely cold or saturated soil conditions foster the growth of thatch in predominantly sandy, acidic, and clay soils. Lawns with warm-season grass will need to be dethatched more often than lawns with cool-season grass. Spreading grasses like bermudagrass and zoysiagrass are warm-season grass that generates massive thatch quantities and must be detached annually. While bunch growing, cool-season grass such as tall fescue and perennial ryegrass seldom develop thatch issues and maybe dethatched every couple of years.

When is the best time to dethatch?

Dethatch your lawn during active grass growth periods to hasten grass recovery, and to bring your lawn back to full health within the shortest possible time. Active growth periods are the peak growing seasons of your lawn grass. These periods fall between spring and fall seasons, depending on the type of grass. Fall and spring seasons are the best time to dethatch lawns with cool-season grass. Dethatch lawns with warm-season grass during their late spring and early summer peak growing periods.

What are the benefits of dethatching?

Dethatching your lawn encourages the flow of essential nutrients into the soil, requiring a constant supply of air, water, and bio-organisms needed to sustain a healthy lawn. Although a thin layer of thatch is highly beneficial to lawns, a thick thatch layer restricts the number of nutrients reaching the soil. Understanding the benefits of regular lawn dethatching goes a long way to encourage homeowners to perform the exercise.

Here are a few benefits of dethatching your lawn.

Dethatching encourages healthy root growth.

Dethatching your lawn facilitates the spread of air within the root zone, which allows the grass to establish deeper and stronger roots to access more soil nutrients, resulting in a greener and thicker lawn.

Prevents lawn disease.

Dethatching lessens the threat posed by lawn fungus and other diseases caused by pests living inside the thick layer of thatch.

Dethatching improves lawn fertilization.

A thick layer of thatch impedes fertilizer and other lawn treatments from reaching the soil surface. Dethatching allows fertilizer to penetrate the lawn soil with ease and release the nutrients needed to grow a lush and healthy lawn.

Dethatching improves the soil water absorption rate.

Removing the excess thatch from your lawn allows water from irrigation or rainfall to penetrate deeper into the soil, improving the soil’s ability to soak water and reducing water runoff.

Dethatching vs. core aeration?

Any lawn keeper knows that the secret to a healthy lawn is a deep and healthy root system. Soil compaction and thatch build-up make it harder for grassroots to access air and water in sufficient quantities for your lawn to thrive. Dethatching and core aeration are lawn procedures that resolve soil compaction and thatch issues, improving the supply of air and water to the lawn root zone. But while dethatching is performed to untangle excessive thatch, lawn keepers perform core aeration to reduce lawn soil compaction and use the procedure as a means of thatch control.

Blue corner: Dethatching

What a thick layer of thatch achieves is to block the soil’s access to nutrients. The process of removing the thatch layer is called dethatching. A significant advantage of dethatching your lawn is that it gives your yard improved resistance to drought, disease and provides the soil with enhanced access to air and water.

Other advantages include:

  • It enhances soil drainage and reduces water pooling.
  • It improves the soil access to sunlight.
  • It increases soil moisture.
    It helps with insect and pest control.
  • It eliminates brown spots, ensuring a green and uniform growing lawn.

Red corner: Core Aeration

Core aeration is that one missing thing you haven’t tried yet when all your attempts to revive your dying lawn isn’t yielding positive results. Core aeration reduces soil compaction by removing plugs of soil from your lawn. These holes act as efficient channels that allow air and water to penetrate deep into the ground. The rush of nutrients into an otherwise starving root area spurs the growth of deeper and healthier roots. It hastens the activities of tiny microbial agents involved in the decomposition of dead organic matter like thatch.

A few advantages of core aeration include:

  • It encourages airflow within the soil structure.
  • It increases your lawn’s fertilizer uptake.
  • It encourages the growth of a thicker lawn.
  • It improves your lawn’s drought tolerance.
    Removes thatch without harming your turfgrass.

DIY dethatching vs. professional service

Homeowners have an option of hiring the services of a landscaping company to dethatch their lawns or perform the procedure by themselves. A DIY enthusiast can complete a small yard in a couple of hours with a dethatching rake, but more extensive grounds need more powerful equipment, like a power rake. The big issue with DIY lawn dethatching is there are a thousand ways to damage your lawn – permanently. Hiring a professional service can save you from making expensive mistakes. Here, we will examine the pros and cons of each option.

DIY Dethatching

Pros

  1. DIY dethatching is an excellent choice for keen lawn keepers eager to spend a bit of outdoor time doing quality lawn work.
  2. You save money by not paying labor costs. And you can also save on rental fees if you own your dethatching equipment.
  3. Working at your own pace allows you to make the necessary number of passes needed to dethatch your entire lawn properly.
  4. It prevents unnecessary grass damage caused by dull blades on poorly maintained dethatching equipment used by some professional lawn services.
  5. It allows you to spot areas on your lawn requiring special attention.

Cons

  1. The cost of renting and transporting dethatching equipment can exceed the cost of hiring a professional service.
  2. Inexperienced do it yourself, dethatchers can make mistakes that may necessitate replacing the entire lawn.
  3. Lack of proper operating knowledge of dethatching equipment may result in operating dethatchers with improper settings, which may remove healthy lawn grass while leaving thatch intact.
  4. Lack of professional guidance may result in homeowners adopting detaching methods that can actually aid the spread of weeds such as crabgrass.
  5. Homeowners’ inadequate knowledge of grass recovery techniques may kill off the grass.

Professional dethatching service

Pros

  1. Professionals offer guidance on the best dethatching and lawn recovery techniques suitable for your grass type.
  2. Professionals work efficiently and quickly to deliver a quality job.
  3. Your lawn benefits from the unique skills and expertise of each member of the team working on your lawn.
  4. Licensed landscaping services carry liability insurance, which covers any damage to your lawn.
  5. Professionals can recommend improvements or modifications to your existing lawn care practices, e.g., suggesting new irrigation or fertilizing methods.

Cons

  1. It can be expensive.

Cost of Professional dethatching of lawn

The pricing of professional dethatching services varies according to location. And the actual lawn service cost will depend on your lawn size, the severity of your thatch problem, and grass type. On average most homeowners spend between $10 to $20 per square feet to dethatch their lawns. Severe thatch problems can cost as high as $40 per square foot.

The quoted prices include the cost of cleaning up the debris left on the lawn after the process is complete. Grass recovery treatments cost extra. Discuss with your lawn service provider if you want it included in your estimate.

ServiceQuantityLowHigh
Lawn Dethatching costSquare feet$10$22
Lawn Dethatching labor costPer Hour$55$85
Dethatching per avg 10,000 sq. ft.10,000 sq. ft.$100$200

Avg. Pro Dethatching for 5000 Sq.ft
Estimate: $475

Should I aerate after dethatching?

Aerating soon after a thorough dethatching is excellent for your lawn because the holes left in the soil helps the grass to expand during its recovery period. Like dethatching, it is better to aerate when the ground has significant amounts of moisture. If you’re not reseeding, apply pre-emergent weed killers to prevent weeds from being established.

Should I overseed after dethatching?

Overseeding after dethatching is an ideal way of reclaiming lost grass tracts to create a lusher and more beautiful lawn. Overseeing is a new beginning of sorts, and you may want to seed a combination of several cultivars of grass seed to improve the look of your lawn.

FAQ's

Dethatching can hurt your lawn, and here’s why. Dethatching machines rip into turfgrass, tearing them out with thatch. When this happens, performing necessary grass recovery techniques is essential to restoring your lawn health. Failure to do so will leave your lawn permanently damaged. Also, detaching during winter and summer periods when your lawn is vulnerable can damage your lawn beyond recovery.

During dethatching, weeds are pulled up along with thatch. However, it is not an effective method for removing weeds from your lawn. Dethatching with a power rake can unearth and disperse crabgrass and other weed seeds across your lawn, setting your yard up for a weed infestation. Lawn keepers are advised to remove weeds before they dethatch.

Dethatching first and aerate afterward produces the best results. By removing the excess thatch and other organic residues from your lawn, you help core aerators effectively penetrate deep into the soil, improving the supply of air, water, and nutrients into the ground to stimulate root growth.

No, the theory that grass clippings cause thatch is a discredited myth. Grass clippings contain 10% nitrogen and 90% water. These are requirements needed to cultivate billions of tiny microbial agents that help decompose thatch.

No, by dethatching your lawn during wet soil conditions or after heavy rainfall, you increase the chances of your grass being pulled out by the dethatcher. Detach only when the ground is moist.

Funso Ogunnowo
Author: Funso Ogunnowo - Funso is a freelance writer with over ten years of experience working as an accountant. His love for writing prompted his foray into the world of freelance writing, and he is active on freelance websites like Upwork, where he has completed several writing projects for different clients.