Top dressing, as the name suggests is a generic term for the application of something to your lawn to improve it in some way. The main two types of dressing are sand, or compost/peat. Sand is applied to improve drainage, and compost to introduce nutrition to a lawn that may be growing in poor quality soil, or is suffering from neglect. You might also add dressing to bulk out holes in the lawn after scarifying or tining.
Top dressing is also often used these days to aid with drainage on artificial turf lawns, so if you ever consider going down this route it’s worth bearing in mind that this will be part of the process.
Applying Top Dressing
For best results apply top dressing after scarifying or tilling, however this is not strictly necessary. The most important thing to remember is not to be too generous with the amount you apply, so it’s best to use a controlled method of laying the material. Whether you use a shovel or a spin spreader, try and be as consistent as possible, and try not to lay more than 5mm. If the visible part of the root of the grass (known as the crown) is smothered in dressing then this will stifle it’s growth, so you must make sure the dressing is worked into the soil once it is laid, not simply left sitting on the top. A tool such as a dragmat will allow you to work the dressing in over a large area, plus if you have a ride on mower you can use that to drag it along, making it an easier job for you!
A note on sand if you are top dressing for drainage purposes, ensure that you are using a horticultural or sports grade sand, as other types may cause damage either through being the wrong size and shape, or through impregnation with harmful oils or chemicals commonly found in building sands.