What is lawn thatching, and does your Fairhaven, MA lawn need it?
- 2 days ago
- 10 min read
By Jorge Melo
Many homeowners in Fairhaven notice their lawn feels spongy underfoot or looks thin despite regular mowing and fertilizing.
When we inspect the turf, the issue is often thatch buildup. Thatch is the dense, spongy layer of dead and living organic matter that builds up between the soil surface and the green grass blades.
This gradual accumulation is sometimes referred to as thatching. The process of removing excess thatch is called dethatching. A layer thicker than half an inch hinders water, air, and nutrient absorption, and that's when mechanical removal, or "dethatching," becomes necessary to prevent lawn damage and disease.
Every lawn produces some thatch, and a thin layer is actually helpful. Homeowners across Fairhaven, Mattapoisett, and Acushnet often call us about lawns that look tired despite regular care, and excessive thatch is one of the most common causes. If your yard feels spongy when you walk across it, thatch buildup may be the reason.
This guide covers how to spot it, what causes it, and when dethatching services make sense for South Coast Massachusetts properties.
What is thatch in a lawn?
Thatch is a tightly woven mat of grass stems, roots, crowns, and other organic debris that forms right at the soil surface. It develops naturally as your lawn grows and sheds material.
Some of that material breaks down quickly through microbial activity, but tougher components like stems and roots decompose slowly.
When production outpaces decomposition, the layer thickens.
A thin layer, roughly a quarter inch, is perfectly normal. The trouble starts when it crosses the half-inch mark.
Many of the properties we maintain through our lawn care services in Fairhaven develop thatch gradually over several seasons, especially when they've never been aerated or dethatched.
What does thatch look like?
Pull back the green blades on your lawn and look at the base. You'll see a brownish, spongy layer sitting between the soil surface and the living grass above. It looks like a dense mat of fibrous material, similar to compressed straw mixed with fine roots.
When thatch is thin, you might not notice it. When it gets thick, your entire lawn starts to feel soft and bouncy underfoot. Your lawn mower wheels may sink slightly into the turf, causing an uneven cut.
On properties around Sconicut Neck where coastal moisture keeps things damp, thick thatch can stay saturated for days, creating conditions that invite fungal diseases.
How thatch develops
Thatch accumulates when your lawn produces organic material faster than soil organisms can decompose it. In healthy soil, earthworms, bacteria, and fungi break down debris efficiently. When something disrupts that balance, thatch piles up.
Several common lawn care mistakes accelerate thatch buildup:
Overfertilizing. Too much nitrogen pushes fast growth and creates more organic material than the soil can process. Common on Acushnet properties where homeowners apply fertilizer without soil testing.
Overwatering. Frequent, shallow watering encourages surface roots and reduces microbial activity deeper in the soil.
Infrequent mowing. Letting grass grow tall and then cutting it short creates excess stem material that breaks down slowly. Following the one-third rule with regular lawn mowing reduces tough organic matter going into the thatch layer.
Heavy pesticide use. These products can kill earthworms and beneficial microorganisms that decompose organic matter.
Acidic soil. Massachusetts soils are naturally acidic, which limits microbial activity. When pH drops below 6.0, decomposition slows.
Soil compaction. Hard, compacted soil discourages decomposing organisms. Properties in East Fairhaven with clay-heavy soil are particularly prone.
Is thatch good or bad?
It depends on thickness.
A thin layer of thatch is beneficial
Thatch under half an inch thick provides real advantages for your turf:
Insulation. It buffers grass roots against temperature swings, which matters during unpredictable South Coast Massachusetts spring and fall weather.
Moisture retention. A thin thatch layer helps soil stay moist between waterings without trapping excess water.
Foot traffic protection. That slight cushion absorbs impact from walking and playing, reducing soil compaction.
Weed suppression. Weed seeds have a harder time reaching soil and germinating through a light layer of thatch.
Too much thatch causes problems
Once thatch exceeds half an inch, those benefits flip into liabilities:
Water and nutrient blockage. Thick thatch intercepts water and fertilizer before they reach roots. Homeowners in Mattapoisett often tell us they've been feeding their lawn for years without results, and this is usually why.
Shallow root growth. Roots grow into the thatch instead of the soil, making the lawn vulnerable to heat, drought, and cold.
Disease and pest habitat. Wet thatch creates conditions for fungal diseases and harbors insects like chinch bugs and grubs.
Mowing difficulty. Mower wheels sink into spongy thatch, causing scalping in some areas.
Grasses that are prone to thatch
Grasses that spread through underground stems (rhizomes) and aboveground runners (stolons) build thatch faster. The most thatch-prone types include Kentucky bluegrass, creeping bent grass, creeping red fescue, Bermudagrass, zoysia grass, and St. Augustine grass.
Bunch-type grasses like tall fescue and perennial ryegrass rarely develop thatch problems. Kentucky bluegrass, however, is a heavy thatch producer and the dominant grass type across Fairhaven and Mattapoisett lawns.
How to check for thatch
Checking for thatch takes about five minutes. Grab a trowel or garden knife and a ruler.
Push a trowel into the turf about three inches deep and cut out a small wedge.
Look at the cross-section. Green grass on top, soil on the bottom, and a brownish fibrous layer in between. That middle layer is thatch.
Press down on the thatch and measure it. Thicker than half an inch means you have a problem.
Repeat in several spots to see if it's widespread or localized.
You can also do a simple feel test. Walk across your lawn. If it feels noticeably spongy, like walking on a mattress, thatch buildup is likely.
Lawns around North Fairhaven that have been maintained for years without aeration often hit this point.
When is thatch a problem?
Thatch becomes a problem when it crosses the half-inch mark and your lawn shows stress despite routine care:
Grass looks thin, pale, or yellow even with regular fertilizing
Dry patches that don't respond to watering
Increased weed pressure where turf has thinned
Recurring fungal issues, particularly during humid Fairhaven summers
Water running off the surface instead of soaking in
A lawn that feels soft and bouncy instead of firm
If you're seeing several of these symptoms, pull a plug and measure. In our 35+ years of business, the lawns that decline fastest are ones where thatch has been ignored for five or more years.
At that point, standard lawn fertilizing and watering can't compensate for roots trapped above the soil line.
How to remove excess thatch (dethatching)
Dethatching is the physical process of tearing through the thatch layer and removing it. For cool-season grasses in Massachusetts, the best window is late summer through early fall. Dethatching during active growth gives your lawn the best chance to recover quickly.
Never dethatch a stressed lawn. If your turf is suffering from drought, disease, or heat damage, wait for conditions to improve.
Dethatching tools
Several tools can handle thatch removal, and the right choice depends on your lawn's size and the severity of the buildup:
Manual dethatching rake. A short-tined rake with curved blades that pulls thatch from the soil. Best for small areas with mild buildup.
Power rake. A motorized tool with rotating tines that dig into the thatch layer. Works well for moderate thatch on medium-sized lawns.
Vertical mower (verticutter). Vertical blades slice through thatch and into the soil. Best for severe thatch over an inch thick.
Tow-behind dethatcher. Attaches to a riding mower for larger Mattapoisett or Rochester properties.
Before dethatching, water your lawn lightly a day or two ahead so the soil is moist but not soggy. After running the equipment, rake up all the debris and remove it from the lawn. The amount of material that comes up often surprises homeowners.
What to do after removing thatch
Dethatching is hard on a lawn. What you do in the days following makes the difference between a lawn that bounces back strong and one that struggles.
After thatch removal:
Overseed immediately. Fall timing lines up perfectly with our aeration and overseeding services and creates ideal conditions for seed-to-soil contact.
Fertilize with a starter formula. New seed needs phosphorus for strong root development.
Water consistently. Keep the soil surface moist for two to three weeks while seed germinates.
Consider core aeration. If your soil is compacted, pairing dethatching with aeration addresses both problems at once.
Benefits of removing excess thatch
Proper thatch removal delivers measurable improvements:
Water and fertilizer reach roots instead of getting trapped at the surface
Deeper root growth makes the lawn more drought-resistant
Better air circulation reduces fungal disease pressure
Overseeding and fertilizer applications become more effective
Mowing becomes smoother and more even
Homeowners across East Fairhaven and Mattapoisett Center who have had dethatching done typically see dramatic improvement within four to six weeks.
How to prevent excess thatch
Prevention is always easier than correction. Good lawn maintenance habits slow thatch accumulation and keep it at a manageable level.
Mow regularly and follow the one-third rule. Never remove more than one-third of the blade height in a single mowing. Consistent mowing keeps organic matter production in check.
Water deeply and infrequently. One to one-and-a-half inches per week, applied in one or two sessions, encourages deep roots and healthy microbial activity. Water between 5 and 9 AM.
Fertilize based on soil test results. Over-applying nitrogen is one of the fastest ways to build thatch. A balanced lawn fertilizing program based on actual soil needs prevents this.
Maintain proper soil pH. A pH between 6.0 and 7.0 supports the microbial life that decomposes thatch. Lime corrects low pH when soil tests call for it.
Aerate annually or biannually. Core aeration breaks up compaction and boosts organisms that decompose thatch. Homes along Sconicut Neck with heavy summer foot traffic benefit from annual aeration.
Professional lawn dethatching services in Fairhaven, MA
Dethatching done poorly can damage your lawn more than the thatch itself. Cutting too deep tears out healthy grass. Dethatching at the wrong time leaves your turf vulnerable without the active growth needed for recovery.
New England Tree & Landscape Inc. provides professional dethatching services across Fairhaven, Mattapoisett, Acushnet, South Rochester, and surrounding South Coast Massachusetts towns.
Our aeration and overseeding page cover our full approach to dethatching, core aeration, overseeding, and slice seeding.
When we dethatch a property, we follow up with overseeding and fertilization to support full recovery. Properties that receive landscaping services in East Fairhaven, MA or landscaping services in Mattapoisett Center through our team get year-round monitoring, so thatch problems are caught early.
Frequently asked questions about lawn thatching
Should you remove thatch before overseeding?
Yes. Overseeding onto a thick thatch layer wastes seed and money. Seeds land on top of the thatch instead of making contact with soil, and germination rates drop dramatically. Removing excess thatch before overseeding gives seed direct access to soil, which is why our aeration and overseeding program in Fairhaven includes thatch assessment as a first step.
Will grass recover after dethatching?
Healthy grass during its active growing season recovers well. The lawn will look rough immediately after, but within three to six weeks new growth fills in, especially if you overseed and fertilize right away. Timing the work for early fall in South Coast Massachusetts gives the longest recovery window before winter.
When is it too late in the season to dethatch?
In Massachusetts, mid-October is generally the latest you should dethatch cool-season grasses. After that, the lawn doesn't have enough active growth time to recover before the ground freezes. Dethatching too late leaves your turf weakened and exposed heading into winter.
What are the risks of dethatching?
Dethatching is mechanical stress on your lawn. Done at the wrong time, too aggressively, or on a stressed lawn, it can tear out healthy grass, expose soil to weed invasion, and cause significant damage. That's why proper timing and technique matter.
What mistakes should you avoid when dethatching?
The biggest mistakes are dethatching during drought or extreme heat, cutting too deep, and failing to follow up with seeding and water. Also avoid dethatching a new lawn that hasn't had time to establish roots. Wait at least two to three years before dethatching newly seeded or sodded turf.
Can excess thatch lead to weed problems?
Absolutely. When thick thatch weakens your lawn, the turf thins and opens gaps where weeds move in. Thatch also blocks pre-emergent herbicides from reaching the soil surface, reducing their effectiveness. Removing excess thatch before applying weed control treatments helps those products work as intended.
What time of year is best for dethatching in Massachusetts?
Late August through early October is the best window for dethatching cool-season grasses in Fairhaven, Mattapoisett, and the wider South Coast area. The grass is actively growing, soil temperatures are warm, and fall moisture supports recovery. This timing also pairs naturally with fall aeration and overseeding.
Is a dethatching rake more effective than a standard garden rake?
A dedicated dethatching rake has shorter, curved tines designed specifically to dig into and pull up thatch. A standard leaf rake or garden rake won't penetrate deep enough to remove compacted thatch. For mild buildup on a small Acushnet lawn, a manual dethatching rake works fine. For heavier thatch or larger properties, power equipment is the better choice.
How do you maintain a dethatching machine?
After each use, remove debris from the tines and underside. Check tine condition and replace any that are bent or worn. Sharpen blades on vertical mowers according to the manufacturer's schedule. Clean, sharp equipment produces better results and causes less turf damage.
What is the correct way to dethatch a lawn?
Mow slightly shorter than normal the day before. Water lightly one to two days ahead. Run the dethatching equipment across the lawn in at least two perpendicular passes. Rake up all debris, overseed bare spots, apply a starter fertilizer, and water consistently for two to three weeks.
Does New England Tree & Landscape provide dethatching in Mattapoisett and Acushnet?
Yes. We serve all of Fairhaven, Mattapoisett, Acushnet, Rochester, and surrounding towns across South Coast Massachusetts. Our dethatching services are part of our broader aeration and overseeding program, and we customize the approach based on your property's specific conditions.
What makes New England Tree & Landscape different from other lawn care companies?
We've been serving the South Coast for over 35 years. Our crews know this area, from the clay-heavy soils near the coast to the sandy conditions inland. We assess every property individually and follow up dethatching with overseeding, fertilization, and ongoing monitoring.
Need help with thatch removal on your Fairhaven, Mattapoisett, or Acushnet property?Â
Contact New England Tree & Landscape at (508) 763-8000 or email request@newenglandtreeandlandscape.com for a free estimate.
Sources
Caayao, Janine. "What Is Thatch in Your Lawn?" LawnStarter, 3 Mar. 2025, www.lawnstarter.com/blog/lawn-care-2/what-is-thatch/.
"Why, When and How to Dethatch Your Lawn." Pennington, www.pennington.com/all-products/grass-seed/resources/why-when-and-how-to-dethatch-your-lawn.
Ioo, Andie. "What Is Dethatching?" Lawn Love, 26 Mar. 2025, lawnlove.com/blog/what-is-dethatching/.
Beaulieu, David. "How and Why to Dethatch a Lawn." The Spruce, 14 Feb. 2026, www.thespruce.com/dethatching-lawns-the-what-why-how-and-when-2131038.
"What Is Dethatching?" The Grounds Guys, 12 June 2025, www.groundsguys.com/blog/what-is-dethatching/.