What is topdressing?
Topdressing a lawn is the process of adding a thin layer of material over the lawn. Typically 1/4 inch – 1/2 inch of compost or other soil amendment is spread across the lawn with shovels, in a throwing action. The material can be worked into the thatch area by raking, washed in with rain or sprinklers, or allowed to settle on its own.
Topdressing’s benefits are so numerous, it’s hard to understand why it is not the foundation for every lawn care program on the planet. As a soil amendment, topdressing can improve soil biology by adding organic matter and the beneficial microorganisms of compost. Soil structure and drainage can be modified by topdressing with sand or other corrective materials. Topdressing regularly can smooth out bumps caused by worm castings and encourages a dense, lush lawn. Topdressing reduces lawn stresses, helps keep thatch under control and acts as a long-term natural fertilizer. Adding organic matter to a lawn by topdressing with compost is the most beneficial cultural practice lawn care has to offer.
How to topdress:
Topdressing can be quite labor intensive and at the very least requires shoveling and moving piles of compost or other topdressing materials. The hard work is worth it though and new machines are now available to save on much of the manual labor. Traditionally, topdressing is spread by the shovelful in a manner that I have always felt was similar to taking a shot with a hockey stick. A smooth, sweeping motion aimed at trying to spread the material as evenly as possible to a depth of 1/4 inch to 1/2 inch. Topdressing machines are also available and consist of a hopper to hold the material with a motorized belt to move the product through the hopper to a spinning disc which spreads it on the lawn. These machines are just beginning to get popular as more and more people request topdressing with compost as part of their lawn care regimen.
When topdressing, it is beneficial to do it in conjunction with other cultural practices like aerating, de-thatching and overseeding. Topdressing after aerating and overseeding is the ideal trio of lawn care chores that will result in a healthier lawn. The aerating opens up the soil, allowing for better air and water movement and reduced compaction. The aeration holes provide the perfect seed bed for overseeding, allowing newer generations of grass to establish and thrive. Lastly, topdressing with compost, helps fill in the holes, covering the seed and allowing for ideal germination conditions with a burst of nutrients as the seedlings establish. It’s a win, win, win, situation.