Battery scarifier S138i
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Lawn Scarifier vs Lawn Dethatcher | Understanding the Difference Between the Two

When it comes to improving airflow, increasing water and nutrient delivery, and boosting the amount of UV your lawn receives, nothing works quite as well as removing thatch from the lawn. While a little bit of thatch can help retain moisture and maintain a steady temperature around the base of a lawn, too much of it can act as a repellent against rain, air, and sunlight.

If your lawn feels spongy when you walk on it, or it’s looking a little worse for wear, chances are that the thatch layer needs to be drastically reduced or removed. When removing thatch, you have two options to choose between - lawn scarifiers and lawn dethatchers. Both work to remove thatch, but there are some differences between them too.

If you’re wondering which is better for dethatching lawns and removing accumulated debris, here are some of the main differences between the two.

Lawn dethatchers

For lawns with light to moderate levels of thatch, a lawn dethatcher provides shallow and gentle dethatching that results in less shock and damage to the root systems. Designed to thin thatch rather than completely remove it, dethatchers ensure a thin layer of thatch remains. This thinned-out layer of thatch helps maintain moisture levels and regulate lawn humidity and temperatures.

Modern lawn dethatchers typically resemble push mowers, with many lawn mower models now featuring in-built dethatching modes or accessories. With finger-like blades that reach down into the grass and pull, tear, and lift the layer of thatch free, the shallow depth gives the operator more control over how much thatch is removed.

Benefits of dethatchers

  • Dethatching improves water and nutrient delivery to the lawn root system.
  • Removing thatch minimises the growth of moss, mildew, and fungi.
  • Dethatching promotes healthier and stronger lawn growth.
  • By leaving some thatch behind, humidity and temperature are stabilised.
  • Airflow around the root system is improved, resulting in better growth.
  • Dethatching results in less shock and damage to the lawn.
Dethatcher for Combi Trimmer

When to dethatch your lawn

As a general rule of thumb, lawns should only be dethatched when the grass is actively growing. This means that dethatching during the lawn's dormant period should be avoided. Of course, a large part of this will depend on the type of lawn you have and whether it’s a warm season or cool season grass.

  • Begin by mowing the lawn to reduce its height, making the layer of thatch easier to reach when dethatching.
  • If the layer of thatch is thicker than 1 inch, you’ll want to perform a more intense dethatching with a scarifier.
  • To maintain a thin and beneficial layer of thatch, aim to dethatch your lawn at least once a year.
  • Avoid dethatching during periods of extended heat and reduced rainfall to help minimise lawn shock.

Lawn scarifier

For lawns with moderate to deep layers of thatch, a lawn dethatcher will likely struggle to remove a sufficient amount of accumulated debris. This is where a lawn scarifier comes into play, helping you manage thatch in lawns. Similar to a dethatcher, modern lawn scarifiers look much like a push-mower. However, instead of horizontally rotating blades, it uses a vertically-rotating cylinder and teeth-like blades to penetrate and remove dense thatch. The thatch is then either deposited into a collection bin or left on the surface of the lawn, ready to be raked up.

If a lawn feels spongy beneath your feet, then a scarifier is likely to provide better results than a dethatcher. The longer you ignore the issue, the thicker the layer of thatch will become - eventually suffocating and dehydrating grass beyond the point of no return. While definitely the more aggressive and intense tool out of the two, a scarifier will provide a less finessed finish, but an improved rate of lawn survival. A great choice is the S 138i Battery Scarifier.

Benefits of scarifiers

  • Removes thick, dense, and fibrous layers of thatch with minimal effort.
  • Drastically increases sunlight, water, nutrients, and airflow to the roots.
  • Stops lawns from feeling spongy or bouncy underfoot.
  • Typically requires fewer sessions to remove thatch and improve health.
  • Minimised the growth of weeds, moss, fungi, and mildew.
  • Can automatically collect and box removed thatch.

When to scarify your lawn

As with a dethatcher, you should aim to scarify your lawn only when it is actively growing. If you own a scarifier and lawn dethatcher, it may be beneficial to use the dethatcher at the start of the growing season to remove any growth since the last use. Again, you’ll also want to mow your lawn before scarifying to ensure as much of the thatch and fibrous growth can be removed as possible.

  • Fescue grass tends to develop thatch quickly and often. Removing thatch can be done at the start of spring and then in Autumn before the risk of frost arrives.
  • While tempting to remove 100% of thatch, it’s best to leave at least 25% of it behind to minimise the risk of surface evaporation and low humidity levels.
  • Avoid scarifying lawns that have been recently laid or reseeded. Doing so could cause damage to young and shallow roots, resulting in the shock and death of the newly planted lawn.

The best tools for lawn dethatching

With a wide range of cutting-edge mowers, attachments, and accessories, along with a variety of dedicated battery-powered scarifiers, finding the perfect solution for your lawn care needs has never been easier. Breathe new life into tired and old lawns and save yourself countless hours of cutting, breaking, and raking to remove thatch manually.

View the full range of Husqvarna lawn care tools online & compare different models, or visit your local authorised Husqvarna dealership for more information and demonstrations.