Top dressing a lawn simply means adding organic material to the surface of the turf. This material is usually a mixture of good-quality soil, sand and a source of humus. The purpose of top dressing is to fill in all the minor low areas that have developed during the season, and to build up an ideal soil layer over the years. For a really first rate turf you should top dress your lawn as needed.
The benefits of top dressing include:
- Grass growth is denser _ the formation of new shoots is stimulated and the layer of top dressing promotes the development of runners.
- Minor depressions are filled in so that a better surface is obtained.
- The soil surface is gradually built up _ thatch tends to decompose in this layer and drought resistance is improved.
- The water-holding capacity of sandy soil is improved.
- Drainage in heavy soil is improved, especially if spiking is carried out as a pre-treatment.
Top dressing mixture
A good top dressing for lawns consists of the right mixture of peat, loam and sand. The ingredients should be fairly dry; thorough mixing is essential before use. If the top dressing is lumpy, then pass it through a 1/4 inch mesh sieve.
PEAT: Buy a fine-grade sphagnum or sedge peat. Well-decomposed leaves are a satisfactory substitute. Garden compost is best avoided _ weed seeds can be a problem. LOAM: This is soil that is neither hard like clay, nor sandy. The consistency should be medium to fine. (Organic material should be less than _ inch in size. ) SAND: Sea sand is not suitable as it must be lime-free. The particle size should not be too large _ avoid coarse grit.
You can also purchase a quality lawn soil.
For lawns on heavy soil _ 1 part Peat, 2 parts Loam, & 4 parts Sand
For lawns on loamy soil _ 1 part Peat, 4 parts Loam, & 2 parts Sand
For lawns on sandy soil _ 2 parts Peat, 4 parts Loam, & 1 part Sand
How to apply top dressing
Spread the top dressing mixture at the rate of 3 lbs. per square yard, using a spade to put down small heaps over the surface. This top dressing must be worked in to soil level with a garden rake so that it is knocked off the grass blades. On no account should the grass be smothered. Use a hose and sprayer to wash the top dressing off of the grass blades.
It is essential to spread the top dressing evenly over the entire surface so that depressions are filled in and no new bumps are created.