The main reason for topdressing is to level the lawn or build it up to the desired level. Topdressing fills holes or low spots and encourages the grass to spread by giving it a medium to grow in.
Successful topdressing requires a few tools and some suitable soil. A good wheelbarrow with an inflatable tyre will make wheeling the soil easier. For shoveling and spreading the soil, an aluminium shovel is priceless. A small level-lawn is also a worthwhile investment for leveling and rubbing the soil in.
Soil selection is up to you but it is best to use a soil that is consistent with the soil that the lawn is growing in. This is usually sandy type loam. I prefer use a clean sandy loam rather than some of the lawn topdressing mixes available today which may claim to contain organic matter and fertiliser. My reasons for this are that a clean soil is easier to work with, resulting in a better looking finished job and you can make more money by fertilizing your client's lawns at a later date. It is up to you as a professional lawn contractors to determine the required amount of soil that is needed to complete the job.
Before you actually spread the soil, make sure the grass is actively growing. Don't top dress dormant grass. You will damage it, if not kill it. A good idea is to give the lawn a fertilize a couple of weeks before topdressing, this will help the grass push through the soil quickly. Also, mow the lawn the day before you do the job. Long grass takes more soil to cover properly and the thicker the soil layer, the harder it is for the grass to emerge.
Doing the Job
Alright, you've fertilized, you've cut the lawn, purchased the soil and you are ready to go, but it looks like rain! DON'T DO IT! Why? Besides making a big mess, wet soil does not rub in well and can sometimes dry like a hard crust on top of the grass, making it very difficult for the grass to grow through.
Okay, now the sun is out, lets get into it. Start by spreading an even layer of soil over the lawn covering the entire area. I've seen many people topdress their lawns but only covering it roughly. If you are going to the trouble, at least make sure you do it right.
Heavy traffic areas frequently become compacted. Nutrient intake is impaired, grasses die off from water-logging in winter, and scalding in hot weather, and thatch often develops. The lack of deep irrigation reduces root depth and the lawn becomes less tolerant to drought or infrequent irrigations. Weakened turf grass is also more susceptible to a number of diseases.
Generally speaking, both thatch and compacted soils cause the same problem in that they prevent intake of nutrients.
For heavily compacted soils, coring needs to be undertaken. This can be done by a coring machine, leaving a hole or cavity in the turf to a depth of about 7.5 – 10 cms. These holes then allow water to penetrate down into the root zone, while at the same time providing adequate drainage. After coring spread Gypsum and coarse sand over the area.
e of days. This will let the grass punch through the soil.