How to Top Dress a Lawn
Top Dressing is the task of applying a mixture of sand and topsoil to the surface of a lawn. The renovation process is based on enhancing the integrity of the existing grass, so as to cause as little damage as possible to what is already there.
You will need to spread the topsoil in an even layer over the surface of the lawn. If need be you can fill in any depressions in the surface and mix in some extra seed.
Using a tru-lute or any flat surface, brush the soil into the existing turf. When you have finished it should be possible to see grass blades protruding above the top dressing soil. This is essential as buried grass will die owing to a lack of light, leaving large bare areas. Once you are satisfied this has been completed, rake the area to remove any large lumps.
The best material to use is rootzone (a mix of sand and soil screened down to 2mm with whatever % of sand/soil you require; 70% sand 30% soil is good ratio to work with).
This can be thrown on by shovel or you can hire a spreader. A good idea if you have to top-dress a large area. Before you top-dress a lawn you can spike or hollow tine (core) the existing turf so that the dressing can be brushed into the hole. This will aid drainage and air movement in the turf itself.
Top dressing can be carried out at any time of year but the autumn and spring are the best times.
A dry top dressing is more expensive (as it has gone through a kiln) but it will fill up the holes more easily and will work its way in with less work from you.
Renovation only requires half the seed recommended for a new lawn. Otherwise, the same techniques apply. Divide the seed in half and sow half in one direction, half the other then rake and water thoroughly.
After care is the same as for a new lawn. Make sure your client understands how important this is. Let the lawn grow 75 -100 mm before the first cut. Reduce the height at each subsequent cut until you achieve the best height for the particular species of grass.
Before long you should have a healthy vigorous new lawn with a minimum of fuss and disruption to your client and in very little time.