Top dressing involves spreading a good quality mix of topsoil or compost on top of the lawn and letting it naturally compact down into the existing soil. The key to a successful organic lawn program is the soil; there are wide variety of beneficial microorganisms and bugs. Beneficial microorganisms include bacteria and fungi found in compost. Beneficial microbes feed and protect the plants from disease.
Top dressing a lawn is beneficial because it:
- it builds up the quality of the soil by improving soil structure
- provides additional nutrients and helps soil retain and release nutrients;
- allows the soil to exchange air with the atmosphere better
- slows down grubs by promoting soil micro-organisms;
- avoids water run off, retaining moisture better and making the lawn more resistant to drought
- improves the drainage of clay soils
- stimulates the grass to produce new roots giving a thicker healthier lawn
- breaks down thatch and grass clippings due to microbes in the new soil.
- levels out the bumps in an uneven lawn
There are different type of topdressing materials such as compost, topsoil, peat most, humus, sand etc. We normally topdress by combining a mixture of loam, sand and peat, percentage of the mixture depending on the type of soil. However, compost is usually the best material for top dressing lawns. The Lite Gardener always uses a use good quality compost to ensure it is weed free.
We will mow the lawn as low as possible before topdressing and aerate the lawn if it has poor soil.
We add (¼ to ½") compost or mix of topsoil to the lawn as a top dressing. We spread topsoil or compost in pile on top of the lawn with a wheelbarrow; slinging it from the piles onto the grass with a shovel. Then we lightly brush the grass with the backside of a rake and down into the lawn. We apply topsoil or compost to lawn at a rate 1 yard³ per 1000 ft²; resulting in a thin layer about 1/3" deep when it is spread out it evenly over the lawn.
After the application, careful watering of the lawn by the homeowner will
help ensure that beneficial microbes will be washed into the soil.
We recommend topdressing once every growing season. The best time for topdressing is after aeration or before overseeding lawns.