Top dressing lawns in lawn care should only ever be applied for two reasons, to level small indentations in the lawn and to add special nutrient mixes to the lawn.
Where the indentations are large or deeper than about 4 cm, the lawn may die of suffocation from the top dressing process and will not send out new shoots and runners to repair the area.
This creates two possible problems.
The first is that a dead layer of lawn thatch and roots will be left behind which can become an area of water logging, or become obtrusive and prevent the recovered lawn area from developing and maintaining a healthy root system, resulting in poor lawn health for many years to come. Eventually the area may need to be repaired again.
It will also be left to the surrounding lawn to spread into, and re-cover the area. This may take a very long time, with an unsightly lawn, and risking ongoing damage from wear, and delaying or preventing any recovery of the affected lawn.
The proper solution is to Raise The Lawn. Which simply means to dig out the affected lawn and put down clean sand in the indentation, and then re-lay the lawn on top.
By removing the lawn in strips like roll on turf is done, the job becomes much easier and cleaner, and can be done easily with a spade.
After reinstalling the turf strips, lightly top dress the lawn to finish the evening out process and the job will be finished.
Recovery times depend on the time of year when the lawn repair is done and how well the lawn is being looked after in that time. A few weeks to a couple of months should complete most repairs.
After repairs, mowing of the area should not be resumed until the lawn has set down adequate roots for recovery. The lawn should no longer be able to be lifted when pulled upwards by hand.
Any time in the active growing season is fine for top dressing indentations, from the beginning of Spring through to a month before Winter. Top dressing with soil mixes can be undertaken at any time of the year.
Yes. It’s really a simple process.
The old practice of top dressing lawns with sand in the belief that it was a proper lawn care regime was wrong. It has no benefits to lawns whatsoever. The result of this continuing practice will only raise the lawn higher and create layers of sand and thatch that will only ever have a detrimental impact on lawn health.