The best single time of the year for top dressing lawns is in the fall for cool season grasses and in the spring for warm season grasses. I’m writing from Montana so we have cool season grasses here. This also allows you to combine other cultural practices such as core aeration and over-seeding with the top dressing for the best results. There are a few methods for topdressing lawns. If you aren’t familiar with the idea of topdressing your lawn please read on.
What is topdressing?
This is the application of compost to add organic matter to your lawn. Since many home lawns have poor quality soil, top dressing becomes even more important. Top dressing is simply a way of adding organic material and restoring the balance to home lawns, building better soil and increasing soil flora. By adding compost to a lawn you will add the benefits of more moisture holding capacity and reduce areas of compaction. You will save money on your water bill when you using compost as a sort of mulch for your lawn which holds twice its weight in water and continues to deliver it to the grass roots. Compost contains valuable nutrients and microbes for healthy soil.
Topdressing best practices
There are a few simple methods of applying topdressing compost. One method is to have your lawn core aerated first. Topdressing combined with core aeration can place organic material deeper into the soil. See picture below of how the compost becomes part of the soil layer and gives grass roots something to grow into. Topdressing can be done with or without core aeration and achieve the same benefits. Compost can be distributed with a spreader such as the EcoLawn top dressing spreader. This motorized unit spreads the compost evenly over the lawn. The other method of spreading is to just use a wheel barrow and make small piles throughout the lawn and rake the compost into the lawn. This is easier than it sounds and will quickly disappear into the grass.
If you decide to add more grass seed, this is also a good time to incorporate over-seeding to your lawn. The grass seed could be added to the compost as it is spread or put on before or after the compost. Make sure to water thoroughly after topdressing with compost to soak it well and keep your lawn from drying out. Especially after core aeration. You lawn will green up quickly after topdressing. See some before and after pictures below.