You’ve probably heard the term “thatch” tossed around in lawn care conversations. Maybe from your neighbour who just dethatched his entire yard and now won’t stop talking about it. Or maybe you’ve noticed your lawn feeling a little spongy underfoot and wondered, what’s going on here?
Let’s break it down.
So… What Is Thatch?
Thatch is a layer of dead and living organic material that sits between the grass blades and the soil. It’s made up of things like grass stems, roots, and crowns (the base of each grass plant), and it builds up over time.
Contrary to popular belief, clippings from mowing aren’t the main culprit—those usually break down quickly and even feed your soil. It’s the slower-decomposing parts of the plant that make up thatch.
A little bit of thatch is totally normal—and even beneficial! A layer under ½ inch thick acts like a cozy mulch blanket. It helps the soil retain moisture, shields it from temperature swings, and cushions foot traffic. Nice, right?
When It Becomes a Problem
Trouble starts when this layer grows too thick—usually more than ¾ of an inch. At that point, it starts acting like a barrier instead of a buffer. Water, air, and nutrients struggle to reach the soil. Roots stay shallow. Grass starts to suffer. The lawn might feel bouncy or “squishy” when you walk on it. And if you’ve ever wondered why your lawn dries out fast even though you just watered it? Thick thatch could be the reason.
Excessive thatch also creates a lovely little hideout for insects, fungi, and disease. Not exactly the party guests you want hanging around.
What Causes Excess Thatch?
A few things can speed up thatch build-up:
- Over-fertilizing – especially with high-nitrogen products – i.e. Consumer Grade Fertilizer that you can find in a big box store.
- Overwatering – shallow, frequent watering encourages shallow roots and more top growth
- Mowing too short – scalping the lawn stresses the grass and contributes to weak root systems
- Grass types – some varieties, like Kentucky bluegrass and creeping red fescue, are more prone to thatch than others
How Do You Deal with It?
If you suspect thatch has taken over, don’t panic. You’ve got a couple of solid options:
1. Dethatching
This involves using a special rake (manual or powered) to pull up the thatch and give your lawn some breathing room. Best done in early fall or spring when the grass is actively growing.
2. Core Aeration
This method pulls plugs of soil out of your lawn, helping break up thatch naturally while also relieving compaction and improving root growth. It’s a win-win.
If the thatch layer is thin and manageable, sticking to good lawn care habits might be all you need to keep it in check.
Prevention: The Secret Weapon
Want to avoid thatch problems altogether? Focus on healthy lawn maintenance:
- Mow high (around 3 inches) and often
- Water deeply but infrequently
- Avoid heavy, frequent fertilization
- Leave your clippings if possible—they break down and return nutrients to the soil
In short: Thatch isn’t the villain some make it out to be—but left unchecked, it can cause big problems for your lawn’s health. Keep it under control, and your grass will thank you.
Want help diagnosing or dethatching your lawn? We’re just a call (or a click) away.
