In many new housing developments, the developer supplies the home with lawn to give the homeowner something green to get him/her started. In many cases, the lawn may look green and healthy for a few seasons, but then gradually deteriorates, leaving unsightly bare patches. Often, no matter how much lawn dressing and fertiliser is applied, the lawn just doesn’t recover completely.
If there is limited traffic on the lawn, it is likely that the problem lies in the condition of the soil. To investigate further, you’ll need to dig to find out what is happening underneath your lawn. In the majority of cases, we find that the lawn was laid directly on builder’s rubble or over an area where the builders did their cement mixing. Here are 2 examples:
The lawn is patchy in this garden, despite efforts at seasonal top dressing and fertilising
Digging the lawn area to a depth of 20-30cm
During digging, bits of rubble become exposed, just below the surface of the lawn
Further digging exposes significant amounts of rubble beneath the lawn
A new lawn (dry kikuyu) is laid by the developer in this new complex garden prior to the home owner moving in
Removing the new lawn and digging below the ground reveals that the lawn was laid on top of a significant amount of building rubble
We removed the building rubble, prepared the soil with new topsoil and compost, and laid new lawn
Preparing your soil
A healthy lawn needs at least 20cm of composted topsoil so that it can send out strong roots to support the plant in times of stress (i.e. dry or extremely cold periods). In order to correct the underlying problems with your lawn, the best option is to remove the lawn, remove any rocks, rubble or debris, and prepare your soil to a depth of 20 - 30cm.
How to prepare your soil for lawn:
- Dig and loosen the soil to a depth of 20 - 30cm
- Remove any stones, rocks, debris or concrete that can impede the growth of your lawn
- Apply compost, about 1 x 60dm bag per 4 square meters, and lightly work it in with a fork
- Apply Superphosphate (and/or bonemeal) to encourage root development, at a rate of 50g per square metre
- Dig over the area again and rake it level
- Check the levels and ensure that runoff and drainage have been considered
- Lightly roll or stamp the area to settle any air pockets and to prevent uneven surfaces
- Rake the soil lightly again to get a fine finish
Once you have completed these tasks you can plant your lawn sods, or lawn plugs. If you are using sods, give the lawn one last roll with the roller once you have planted it, again to remove any air pockets and to settle it into your ground.