The most popular lawn varieties in WA are what we call warm season grasses, which are the couch and buffalo cultivars. These grasses thrive in the warm weather, but at this time of the year tend to look a little yellow and tired.
So it’s time to give lawns a kick start to get them looking gorgeous over spring and summer. A little work over the next few weeks saves hours of harder work in summer. The majority of lawns grown in WA are in sandy soils so the water drains through quickly and there is a high risk of fertiliser leaching into our waterways. It’s not difficult to keep the lawn looking great and protecting the environment at the same time. Controlled and slow release fertilisers are the future when it comes to applying nutrients to the garden and none more so than in the case of lawns. These types of fertilisers are perfect as they release nutrients slowly as the lawn needs them and will not leach past the root zone in a matter of days, which is what happens with a totally soluble fertiliser.
The most important reason we apply nutrients at this time of the year is to strengthen the root system of the plant and thicken the cell walls. This is what makes the difference to your lawn surviving or thriving throughout the summer months when the hot weather sets in.
If your lawn is spongy now is the time to put the vertimower through it. In the case of a buffalo lawn, avoid the vertimower and run the mower over it with the blade set very low, you will be almost scalping the lawn. Both these practices will reduce the build-up of thatch or organic matter and will reduce water usage through summer.
We also need to treat the broad leaf weeds before they go to seed. At this time of year, some lawns are so infested with weeds that it can be difficult to see the actual grass. Usually they can be pulled out, but if you have more than a few weeds they can be sprayed with a selective broadleaf weed killer.
However, buffalo lawn has a broader leaf than a couch lawn and the way the selective broad leaf weed killers work is that they sit on the foliage and are absorbed by the plant. On a couch lawn, because it is finer and more upright, the herbicide runs off and isn’t absorbed. So, when selecting a product off the shelf remember that those products which contain Dicamba are safe for couch lawns but are not suitable for buffalo or kikuyu. Controlling weeds in a buffalo or kikuyu lawn requires a product that contains the active ingredient called Bromoxynil. It’s easy to identify, just check that it’s written on the container.
Written by Sue McDougall, a qualified horticulturalist and experienced garden centre owner who grew up in the WA wheatbelt and has had experience in gardening throughout the entire state. You may know Sue as the garden expert on 6PR radio and by her many TV appearances.