SCARIFYING 

Lawn scarification involves using tools or machines to mechanically remove and manage the build-up of organic material in lawns. This material, known as lawn thatch, consists mainly of dead grass roots, shoots, and runners. It sits among the grass plants, just above the soil.

Scarifying removes thatch and revitalizes your lawn by allowing essential air, water, and nutrients to penetrate the soil. It promotes new growth and helps break down organic material, slowing its build up over time. The result is a greener, denser, and healthier lawn.

 

What is Lawn Thatch?

Lawn thatch is a fibrous layer made up of mostly dead and some living grass roots, stems, and runners. It sits between the grass leaves above the surface and the root system below

Microbes, bacteria, and fungi in the soil naturally break it down and decompose it over time.

Ideally, it would decompose at the same rate as new grass grows, preventing any issues.

However, thatch contains lignin, a chemical compound that breaks down slowly. Since perfect conditions are rare, new grass often grows faster than the dead material decomposes, causing thatch to accumulate.

The Pros and Cons of Lawn Thatch

Lawn thatch can be both helpful and problematic. A thin layer (around a quarter of an inch) is good, as it protects the grass crown from damage and disease while still letting water, oxygen, and nutrients reach the roots. It also helps keep the soil moist in summer and prevents freezing in winter. But too much thatch (half an inch or more) can cause problems for your lawn.

Lawn thatch builds up when new grass grows faster than old, dead material can decompose. The breakdown of thatch depends on the soil’s microbial activity, which is influenced by factors like:

Over fertilising is one of the biggest causes of the accumulation of lawn thatch.

Lawn feed contains nitrogen, which makes grass grow quickly. Applying too much fertilizer or using it too often causes grass to grow faster than soil microbes can break down the dead material. Different soils have varying amounts of microorganisms, bacteria, and fungi. For instance, clay-heavy soils often lack oxygen, resulting in low microbial activity and faster thatch build up. Loamy soils, on the other hand, are rich in bacteria and microbes, slowing down thatch accumulation. Similarly, compacted soils lack oxygen, preventing microorganisms from decomposing organic matter, leading to more thatch. Overwatering or shallow watering encourages shallow grass roots, which can also increase thatch growth. Ornamental lawns with bent grasses and fescue grasses tend to produce more thatch because of their spreading growth habit. However, different types of these grasses vary in how much thatch they produce. Ryegrass, which grows in tufts instead of spreading, doesn’t create any thatch, making ryegrass lawns easier to maintain, especially for those less experienced with lawn care.

The Grass Becomes Weak and Sparse

Normally, water delivers oxygen and nutrients into the soil, where grass roots absorb them. However, when there’s too much thatch, these nutrients can’t reach the soil, leaving the grass deprived of what it needs to grow and thrive. As a result, the grass becomes thin and weak. Sometimes, the grass will extend its roots into the thatch layer to access the trapped water and nutrients, which only worsens the issue.

An Increased Risk of Drought Damage

Thatch creates a barrier that stops water from reaching the soil, causing it to dry out. This leads the grass to grow roots into the thatch instead. During the summer heat, the thatch becomes extremely dry as moisture evaporates, leaving the grass without the water it needs to survive.

Moss and Fungal Disease Start to Spore

Lawn thatch blocks water from reaching the soil, causing it to accumulate on the surface and within the fibrous layer during rainfall. In autumn and winter, this surface moisture creates an ideal environment for moss and fungal diseases to spore and spread rapidly.

There are plenty of ways to keep our lawns healthy and ready to withstand hot summers and harsh winters. Scarifying is a more intense method that effectively removes unwanted build-up around delicate grass blades and roots. Falling somewhere between dethatching and tilling, scarifying can be a great option if done carefully and correctly.

Scarifying is the process of digging into a lawn to remove accumulated yard debris and grass clippings from the soil surface and underneath. Like a milling machine, sharp blades cut into the ground, shredding everything in their path. It’s a crucial step for neglected lawns needing more than routine care or for tackling stubborn thatch.

A properly scarified lawn is the perfect base for new turf to be laid down and can help prevent prevalent weeds from establishing early.  Scarifying helps keep your lawn healthy by preventing it from suffocating under a thick layer of thatch and providing essential aeration after a hot summer. When compaction and thatch build up start affecting your turf, it’s time to scarify.