Why apply top dressing to soil

Why Apply Top Dressing

This is the process of adding material to the surface of the lawn grass - usually loam or sandy loam mixes, sand or organic material.

Lawn top dressing is the process of adding material to the surface of the lawn. This would normally be loam or sandy loam mixes, sand or organic material.

Top dressing has a number of benefits:

  • Smoothing the lawn surface
  • Helps control thatch
  • Improves the soil
  • Improves drainage over time with repeated applications
  • Helps in renovating or over seeding
  • Protects the grass over winter

When adding top dressing you must recognise that what you add will eventually become part of the root zone (the soil where the roots grow best) and therefore needs to be able to blend over time with the existing soil. Thus, adding ¼” of sharp sand to a lawn which is on ten inches of heavy clay will not mix and have next to no benefit.

Who Should Top Dress the Lawn?

Top dressing, if done correctly is expensive (particularly if you are using a sterilised weed free material), hard work and time consuming. If you can realise many or all of the benefits above then it is an invaluable addition to your lawn care regime. However, in practice you are only likely to top dress your lawn for two reasons.

Firstly, and for 99% of you, it will be to smooth the lawn surface regardless of lawn quality, type or usage. If you have minor bumps and undulations that spoil the lawn's appearance or cause the lawn mower to bounce, then by all means, top dress. Quite often, you won’t be able to resolve the problem all in one go, and several top dressings will be required. Note: If the bumps and hollows are severe, they may require surgery (see Bumps and Hollows halfway down this page).

Secondly, you are an enthusiast with perfection in mind. In this case only minor undulations may be present but your lawn will benefit in many other ways by the addition of top dressing.