While we like to think that most lawn fanatics know what thatch is, this brief outline will not only help in control of thatch, it will help our new fanatics understand what thatch is.
What is thatch?
To put it simply, thatch is a natural part of the plants growing structure. Thatch can be simply identified as that part of organic material hiding in the canopy of your lawn, you know the dead and brownish material lurking below our nice, green top.
Thatch is a make-up of different parts of the plant which can include stem, roots, crowns, etc. Thatch will also contain an amount of lawn clippings as there is not one mower in the world that can guarantee 100% every blade that is cut is completely removed. Lawn clippings are not the biggest issue though. For years and even here on the page a lot of people are under the impression that lawn clippings contribute to thatch. This is said by the professionals to be “A false and misleading statement,“ as grass clippings are mostly water and are broken down easily by the microbial activity in your lawn. There is a good tip right there; a healthy lawn is not just fertiliser and water - a lot comes down to your microbe activity.
Thatch, like other good lawn maintenance practices, has tended to be overlooked in the past. Over the past few years we have tried to educate people about thatch and now it has become very important step for many during renovations to achieve the best results.
Thatch does have a place in the lawn when controlled. A lot of people wouldn’t realise that in minor amounts, thatch is beneficial and can help protect your profile from overheating and acting like an umbrella in a heat wave. Thatch can also help in weed control if you have no thatch seeds, it is able to penetrate straight down to the soil allowing them contact and a chance to germinate.
What happens when there’s too much thatch?
Let’s have a look at what happens when there is too much thatch. A dense thatch layer can have adverse effects like suffocating your turf and limiting the amount of water, nutrients and oxygen that get to where they are needed most. When using products such as Acelepryn and pre-emergents, a thick thatch layer can trap and lock an amount of the product up and prevent them from effectively entering the soil layer.
Identifying and managing thatch:
As stated earlier, thatch can be easily identified. You can also tell when mowing. How? Scalping. You know when the mower bites in and literally chews your lawn, leaving brown cut marks that you didn’t have before? Apart from undulations, thatch can also be a cause of scalping. Parts of your lawn may contain different thicknesses of thatch levels therefore allowing your mower to sink in those areas causing it to cut a lot lower, damaging the turf and exposing the thatch layer.
The good news is that thatch can be managed and it’s really not as hard as you might think. Probably the biggest thing to avoid are those quick release fertilisers broadcasting urea and high nitrogen fertilisers that promote growth and will increase your thatch rate as the plant goes through a series of growth flushes. Slow release gently feed the plant over a period of months which is why we recommend only trusted varieties like Turfmaxx and Maintain.
Removing thatch from your lawn:
Now that everyone has a better idea of what that thatch is, it’s time to give some pointers in the removal of thatch. Take note: Dethatching can be stressful for your lawn. This should be attempted only when the plant is growing. This will differ according to where you live as down south stays cooler for longer, so don’t rush in if you see people in Queensland dethatching if you live in Victoria as soil temps and growth rates will be completely different.
Removing your thatch can be done in two ways: by machine and/or the hard slog. Specialised machines such as vertimowers and dethatchers tend to make light work of your thatch. These machines can be set to allow the tines or blades to enter your thatch layer. As they spin, they basically grab and pull the organic and dead material to the surface. When using these types of machines, dropping them on their lowest setting from the start and hoping to remove your thatch in one hit is not the way to go about it. If you are hiring a machine and it is the first time you have ever attempted this, it is wise to ease into it. Set the machine to a reasonable height do a pass and to inspect:
- How much thatch appears on the surface
- How much is left in the canopy.
Adjust your height if needed and repeat the process until your happy, remembering that couch lawns can take a lot more punishment then other varieties. Be extra careful with Buffalo as to not shred the plant and do excessive damage to the above ground stolons. If you are concerned or worried by any of the above, a contractor who knows what they are doing will be able to help.
If money is an issue then it’s the hard slog, using a dethatching rake and/or a steel tined rake and raking the surface of your lawn will achieve a solid result (and you will have earned your knock off beverage). Clean up is easy, too. Use your rotary mower as a vacuum to remove the thatch that has been brought to the surface and complete several passes until your happy you have picked up as much as you possibly can. When using your rotary to clean up, set your machine to a desired height, low enough to lift the thatch from the surface - not a scalping height.
This growing season remember to maintain regular mowing practices. Keep a good watering schedule, aerate and use stabilised forms of fertiliser. These simple practices, along with a healthy amount of microbiology, will help manage your thatch layer. They won’t eliminate it but will certainly help, as thatch is part of the plant’s normal life cycle.
Every turf grass suffers from thatch (some more than others) so we are all in the same boat! Trying to keep it simple, we hope you now have a better understanding of thatch.