How do I remove thatch from my lawn?
You may have noticed a build-up of dead organic matter and excess roots and stems within the profile of your grass. This material, known as ‘thatch’, builds up naturally as your lawn produces organic matter at a faster rate than it can be broken down. Over time, the height of your lawn can increase to the point that it becomes quite unsightly. Some turf varieties thatch more than others.
So what do you do if your lawn is overrun with thatch?
Dethatching is the removal of thatch to allow air and nutrients to reach your soil base and feed your lawn. Reducing thatch also prevents waterlogged roots and allows proper drainage, helping reduce the risk of fungal infection. Dethatching works only for warm-season grasses such as Sir Walter Buffalo and Eureka Kikuyu Premium VG and Couch varieties such as Santa Ana and Tif Tuf. This is because typically warm-season grasses are runner grasses, rather than seed grown cool-season grass.
If your lawn feels ‘spongy’ to walk on, it may be time for action! However, dethatching should only be done once a year towards the end of spring (around October/November in Melbourne), when the lawn is in a phase of growth and will be able to recover quickly and effectively. Do not do this in the cooler months, as the lawn will not be able to recover.
Here are a few different ways to remove thatch from your lawn.
Mow low
Towards the end of Spring (Oct/Nov) mow your lawn, then lower the mower height by one or two notches and mow again. Ensure you keep the catcher on your mower to catch all clippings. Repeat this method until you have cut down to the ground for Couch or Kikuyu varieties or just until you have cut 60 – 70% of the leave off Buffalo varieties. As mentioned above, however, be careful to do this at the end of spring so that the lawn is in the right condition to recover.
Use a dethatching rake
Raking with a dethatching rake is one of the easiest and least invasive ways to remove built-up thatch. The rake digs in to pull the thatch out from within the grass. If you have a substantial thatch build-up, however, you may need to look at a more disruptive method.
Use a specialised dethatching machine
You can hire or purchase specialised dethatching machines – vertical cutters, verticutters, or power rakes – that make light work of removing the thatch layer. This can be a good option if you have a large lawn or if the thatch layer hasn’t been tended to for a number of years and is especially thick. Be sure to find out the recommended cutting height for your lawn type and follow the instructions carefully.
After dethatching your lawn, it will be in pretty poor shape. Make sure you rake up all the loosened debris and fertilise your lawn to help it to recover.