Does your lawn look worse after a mow? Are there circular spots of dry frayed grass after the mow? I’m sorry to tell you but it’s highly likely you have thatch. Don’t be alarmed you don’t need to see a GP. The cure is in your garage or shed. Your lawn is about to be “dethatched”. The lawn equivalent of the cruelest cut.
Thatch is a build of dead grass leaves, stolons and rhizomes in your lawn. It can leave your lawn looking unsightly after it is mown and reduces water infiltration making the lawn less drought tolerant.
Head to the shed and get out the mower. You are about to butcher your lawn by giving it the equivalent of a skinhead haircut better known as scalping.
Scalping the turf to remove thatch can be achieved by setting the mower as low as possible and mowing with a catcher. Remove all of the clippings.
Thatch removal in warm season grasses is best carried out from late October to early December.
Prior to October warm season grasses are still recovering from winter and developing new shoots and energy stores in the root system as well as producing new roots, rhizomes and stolons. Scalping at this early stage will result in a slow recovery and provide bare areas for weed seed to develop in.
In the case of Couch and Kikuyu scalp the lawn as much as possible. Buffalo should not be scalped back to bare earth as it will not recover. Stolons and some leaf need to be left in the case of Buffalo. The same applies to Blue Couch.
A rake can also be used to remove dead leaf material in Buffalo and Blue couch lawns and if used aggressively will have a similar effect to moderate low mowing. Remove the dead vegetative material following raking.
Feed the lawn immediately after scalping with Lawn Food Fertiliser and irrigate. The use of a wetting agent at this stage will also benefit water penetration through what is probably a hydrophobic (water repelling) surface layer.
A scarifier machine is also useful to remove thatch and Couches benefit from this. Do not scarify or scalp after January. Scarifiers can be hired.
Coring is sometimes suggested as a means of thatch removal. This is a fallacy as only 8-12% of the surface matt is removed with a conventional Core pass. Coring is used to open up the surface to oxygenate the profile and “unseal the surface” prior to topdressing. It also provides an entry point for topsoil to get into the old soil profile if topdressed immediately after coring. Removing lawn clippings aids in slowing thatch development and we encourage this practice.
Do not scalp the lawn in its first spring season if it was laid in late autumn or winter. It is still a baby in its lifespan and needs to develop a strong root system to get it through its first summer.
Your lawn will look a mess for a few weeks. It will recover and look perfect very quickly and the benefits of the scalping will show throughout summer.