Now is the time of year to start talking about thatch and how to can remove any thatch which may have developed in your lawn over the winter months. So in this blog we're going to discuss what thatch is, why it’s dangerous for your lawn and how to use scarifying techniques to reduce the thatch in your lawn. Thatch is an issue many people do not know about. When you see some of the striped lawn photos we post they have all been scarifying their lawns and have the healthiest grass possible. Please be careful there is no frost around in the forecast ahead of scarifying.
What is thatch?
First things first, what is thatch? Thatch is an organic layer in your lawn consisting of dead, dying and living roots, stems and leaves which is between the layer of grown grass and the soil below. You can often tell that your lawn has a high volume of thatch if your lawn has a spongy feeling to it when you stand or walk on it. The thatch layer usually forms when the organic matter which has failed to break down in the soil builds up beneath the grass plant. This layer can then prevent water, air and nutrients from reaching the roots of your lawn. This is usually something which happens when the turf develops organic debris faster than it can be broken down. It can also consist of leaves that have decayed into your grass. Having a small amount of thatch can be a good thing- we suggest about a quarter of an inch. A smaller layer of thatch can protect the crown of the grass plant from disease- anymore than this and you will start to see serious issues.
Why is it a problem?
So now we know what thatch is but not why it can be bad for the health of your lawn. Well, we’ve touched on this briefly already but to go into more detail, as thatch thickens it will begin to prevent your lawn from getting the air, water and nutrients it needs to grow. Water carries oxygen and nutrients into the soil to the grass roots. When the thatch levels are too thick this water cannot pass through and therefore the grass is starved. This reduced flow of water can cause major issues in wet conditions where the water cannot drain through the soil. It can also cause a build up of moss and fungal diseases which thrive in damp conditions as well as causing issues in dry conditions where the thatch stops the grass plant receiving water. If you put fertiliser on your lawn it will just sit on top of the thatch layer and not pass through. Thatch can also harbour weeds.
If you notice the above photo the left shows a thick thatch layer which is reducing the length of the grass roots. A shorter grass root makes the grass struggle to find water which will therefore make the grass sparse. In the middle section the scarifying process has taken place and you can see water, oxygen and nutrients are able to reach the grass roots. The section on the right hand side shows the lawn post scarification. You can see the grass roots have lengthened allowing the grass to find all the water and nutrients it needs.
How to Dethatch
When it comes to dethatching your lawn, removing moss and any other dead organic matter we’d recommend the scarifying process over anything else, and we’d advise to scarify little and often! Some homeowners scarify their lawn twice a year, once in March or April and again around September/October time however we suggest scarifying with our spring rake cartridge at least once a month. How to reduce the layer of thatch on your lawn is pretty simple and straight forward, and involves quite a mechanical exercise. In order to tackle the build-up of thatch you need to be cutting into the thatch a little bit at a time as you won’t be able to eliminate the thatch layer all in one go, and possibly the simplest way to do this is with a rake. However, no matter what size lawn you have and how much of your lawn is affected by thatch, reducing the thatch manually with a rake will be hard work Here at Allett Mowers, we’ve come up with some other solutions in order to not only rake and mechanically remove thatch, but to also collect the thatch simultaneously along with any other debris present, to allow you to complete this process faster and more efficiently without using harmful chemicals. These solutions include a range of Allett cartridges that you can place into your machine including our Verticutter, Dethatcher and Scarifier
Scarifier Cartridge - Use at least once a month as aggressively as you wish
The Scarifier cartridge is Allett’s most popular cultivation cartridge and is designed to remove thatch, surface debris and dead moss. This cartridge also helps lift lateral growth upright before mowing. The cartridge is designed with rotating spring tines that pull out the dead grass and moss to enable the passage of nutrients into the soil, with ease. The rotating spring tines are relatively gentle on the lawn and this cartridge can be used most of the year without fear of damage to keep on top of thatch levels as well as being useful to collect up leaves, pine cones and pine needles during the autumn.
Find a video on the Scarifier cartridge here
Dethatcher Cartridge- For lawns in serious disarray or usage twice a year.
Boasting wider spaced, thicker tines the Dethatcher is the most aggressive cartridge and penetrates the soil to a maximum depth of 6mm. For lawns in serious disarray, the Dethatcher removes the densest layers of thatch effectively. This cartridge works by rigorously penetrating the soil’s surface in order to pick up and remove layers of thatch such as dead grass and leaves, plant stolons and weed growth. Lawns grow healthier, thicker and more luscious once this has been removed as it its less susceptible to disease. Lawns that are more susceptible to disease encourage moss growth which should be avoided. You would use this cartridge on a lawn with severe thatch problems ahead of top dressing- maybe in March/April time then again in September/October- you would not use this cartridge all year round.
Verticut cartridge- At least once a month
Thin and closely spaced blades effectively lift lateral growth and remove moss which helps encourage tillering and new growth. The blades of the Verticut cartridge help pick up flat lying grasses that your cylinder would otherwise miss. Verticutting can be carried out on a more frequent basis, and is the perfect way to keep on top of your thatch level when set more deeply. The verticut cartridge cuts rhizomes and stolons promoting new growth and therefore thickening your lawn.
The aims of verticutting are as follows
- To prune the grasses to improve tillering and stolon formation. This increases turf density
- To control thatch. The verticut cartridge blades are designed to be used above the thatch layer to remove dead and dying grass plants that will ultimately contribute to the thatch layer.
- To produce an upright grass prior to mowing to give a cleaner more consistent cut.
- As a method of controlling weeds and weed grasses without using harmful chemicals
- Verticutting will also help remove annual meadow grass seed heads and promote finer grasses, such as bent and fescue.
Find a video on verticutting HERE