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Dethatching lawn in autumn: why is it important for your grass and how to properly care for the lawn?

“Organic” is usually a good thing, but organic turf can become a problem that requires dethatching the lawn. Here’s why. Imagine a lawn with three tiers. The blades of grass themselves: This is the layer you are looking at. You will observe the results of your lawn care at this level, but much of the “action” takes place at a lower level. The other levels are the soil and the thatch layer between the blades of grass and the soil. A green lawn starts with good soil, where the roots of your grass are located. And to keep the soil in good condition, you need to dethatch your lawn in the fall. Below we explain why and how to do it.

What is a good soil

An ideal soil is one that is kept evenly moist

An ideal soil is one that

  • is kept evenly moist
  • has good aeration
  • has a pH value of about 6.5
  • is sufficiently supplied with nutrients

What does scarifying mean

If you do it yourself, you can scarify your lawn in three ways

Turf is an organic layer consisting mainly of grass blades (living and dead), stolons and rhizomes that have not yet decomposed. Excessive sod leads to poor grass growth, so the lawn should be kept clean. Removing this turf with a rake is called dethatching.

When to maintain your turf

Dethatching your lawn in the fall - Why it's important for your grass and how to properly care for your lawn

Always check the turf before dethatching. Take a garden trowel or spade and dig up a small portion of the turf and soil. This will allow you to see and measure the thatch layer. If the sod is 1 to 2 inches or more, you’ve probably already noticed signs of poor turf color and weak, thin growth. If you’ve noticed that the turf is exceeding the healthy range, it’s time to dethatch the lawn .

As with most major lawn projects, such as new lawn installation or reseeding existing turf, dethatching should coincide with the peak growing season for your grass species. Active grass growth will help your lawn recover faster. Dethatch cool-season grasses, in late summer or early fall. You should dethatch warm-season grasses after they have flourished in the spring, when they are at their peak in early summer. Never dethatch when your lawn is dormant or stressed; you can damage it so much that it will not recover.

Dethatch or aerate (aerify) lawns in the fall.

Take a garden trowel or spade and dig up a small portion of the lawn and soil


These are two different procedures, but they can work together to help your lawn. Aerification removes soil cores, including the thatch layer, and creates pathways for water and nutrients to penetrate the thatch layer and compacted soil. This prepares the turf for removal and accelerates the breakdown of the existing turf. Dethatching helps to cut the turf into the soil and remove the barrier of thick, accumulated organic material.

How to dethatch your lawn in the fall

Power rakes are mower-like devices with rotating tines that dig into and pull up the sod

If your turf is more than 5 inches thick, you should take action. Excessive matting may require more than one pass, and removing too much at once can damage grass roots. If you do it yourself, you can scarify your lawn in three ways:

  • Manual dethatching rakes are heavy, short-tine rakes with curved blades that dig into the lawn and pull out the sod as they rake. Scarifying rakes are good for light tangles and general maintenance of small lawns with tangles.
  • Power rakes are mower-like tools with rotating, rake-like tines that dig into and pull up the turf. Power rakes are good for lawns with thinner thatch layers and grass that can tolerate intensive raking.
  • Vertical mowers, also called scarifiers, have vertical blades that cut through the turf into the soil, pulling the turf – and often the grass roots – to the surface. Scarifiers are best for thick sod on lawns in need of renovation. Blades can be adjusted to control how much grass is removed at a time.

What to do after lawn care

Dethatching lawn in autumn - The most important thing after dethatching is cleaning it up


The most important thing to do after dethatching is clean up. Remove any debris that you have picked up. After that, it’s time to pamper your lawn. It needs nutrients and is ready to use whatever you give it, so water and fertilize it. If you do this during your lawn’s growing season, the grass will be as good as new for the year.

By choosing high-quality lawn seed to reseed after you dethatch your lawn in the fall, you’ll improve the sustainability of your lawn while you overcome matting.

How to prevent problems with matting.

How to prevent future problems with matting

To prevent future problems with matting, test your lawn’s soil every 3 to 4 years and follow soil test recommendations to keep soil pH and nutrients at optimal levels to keep your lawn growing thick and healthy. Your lawn may need lime to restore soil pH balance, which also promotes beneficial microbial activity that reduces crusting.

Aerate heavy or compacted lawns annually and amend with gypsum to loosen the soil and encourage root growth. Fertilize your lawn according to soil test recommendations with the best lawn fertilizers to ensure it gets the nitrogen it needs without overfertilizing it, and follow best practices for mowing and proper watering.

Knowing why, when and how to properly dethatch your lawn and taking steps to prevent tangles can keep your lawn on the path to healthy, dense and lush growth.