Step1
Determine if the Lawn Needs Dethatching
Wondering when is the best time to dethatch a lawn? If water runs off without penetrating the grass, then it may be time to dethatch the lawn. Thatch is a thin layer of organic debris that forms between the leaf blades and roots. Examine your grass for an underlying layer of thatch. It will look like a matting of old, grayish-brown grass stems that have grown together.
A thin layer of thatch (½ inch or less) provides insulation against temperature extremes and fluctuations in soil moisture. However, if your lawn has more than one-inch layer of thatch above the soil surface, the lawn needs to be dethatched.
Primary causes of thatch are overwatering, over fertilizing, and mowing too high. To help prevent thatch from forming, use a mulching mower.
Step 2
How to Dethatch the Lawn
For northern grass the best time to dethatch your entire lawn is in late summer to early fall when the grass is actively growing. For southern grasses, dethatch in late spring.
In early spring, and for small areas, use a thatching rake, which is a sharp-tined rake that rips the thatch out of the lawn. Leaf rakes or hard rakes can be used but may not work as well. Rake the grass, digging deep to penetrate the thatch and loosen it apart. In early spring removing thatch by raking is best to prevent damaging new growth.
When dethatching your entire lawn use a power dethatcher over the lawn in a pattern that covers the grass only once. Flag irrigation heads and other hidden objects in the lawn to prevent damage. When the task is finished, the lawn will look terrible, but don't panic. It's supposed to look that way.
You can rent a power dethatcher from most garden centers. Enlist the help of a couple of friends and a truck when picking up the equipment, it will be heavy and awkward. Read the operator's manual carefully prior to use.
FAQs
Dethatching your lawn may be as simple as using a stiff spring-tined fan rake to remove an excessive layer of dead organic materal between the green of your grass and the soil.
What is the best month to dethatch your lawn? ›
The best time to dethatch is late summer or early fall. That's when your grass is growing most vigorously. Before dethatching, mow a little shorter than normal. Also, you'll achieve better results if you do it after a light rain or watering.
Should you cut grass before dethatching? ›
Soil must be moist for ideal results. It's also recommended that you mow the lawn half its normal height right before dethatching.
How to tell if a lawn needs dethatching? ›
The easiest is to check to see if your lawn is green on top but brown below. The best time to check is after you mow when you've just cut off the top green growth. If you have thatch, the lawn will look brown or dead. Another test is to walk across the lawn: If it feels spongy, it may be due to thatch.
Is dethatching hard on grass? ›
Dethatch warm-season grasses, such as Bermudagrass or Zoysia grass, after spring green-up, as they enter early summer's peak growth. Never dethatch when your lawn is dormant or stressed; you can damage it beyond recovery.
Will grass grow back after dethatching? ›
After dethatching your lawn it is a great time to aerate your lawn. After aerating, overseed and fertilize with Milorganite®. It should take about 3-4 weeks for the lawn to recover and show signs of new growth.
What happens if you never dethatch your lawn? ›
By removing thatch, you're allowing air, water, and nutrients to reach the root zone of your grass. This helps promote a healthy lawn. A thick layer of thatch can prevent water, air, and nutrients from reaching the roots of your grass. This can lead to a host of problems, including drought stress, disease, and pests.
Do I need to reseed after dethatching? ›
For established turf with bare or weakened thinning areas, professionals tend to dethatch and overseed at the same time. Dethatching first to remove any matted thatch and then overseed. Doing both allows for the best possible penetration of seed and root establishment to quickly thicken up the turf.
Should I dethatch or aerate? ›
Lawn dethatching and lawn aerating accomplish the same goal, but a lawn aeration service does so without the possibility of damaging your lawn in the way that a lawn dethatching service would. That's why dethatching is not considered the best option.
How to get rid of thatch naturally? ›
Applying compost tea regularly
It's compost brewed in water over several hours to create a liquid solution that has extracted all the nutrients and power from the compost material. Regular applications of compost tea can do wonders for the soil and can also help to break down the thatch layer underneath the lawn.
Thatch builds up over time, so it's not necessary to dethatch every year. Plan on doing it every five years or so if your lawn needs it. You might want to give your lawn a quick check every year just to see how much thatch has accumulated.
Should I put grass seed down after dethatching? ›
For established turf with bare or weakened thinning areas, professionals tend to dethatch and overseed at the same time. Dethatching first to remove any matted thatch and then overseed. Doing both allows for the best possible penetration of seed and root establishment to quickly thicken up the turf.
Which is better, Power rake or dethatcher? ›
A power rake is a machine that uses blades similar to a roto-tiller to remove thatch and debris that can build up on a lawn. Power raking is gentler than dethatching since it only removes debris at the soil level (whereas dethatching also pulls and removes healthy root systems).
