Why Top Dress?
There are only 2 reasons you would ever need to top dress a new or established lawn. The first is to improve the level, fill in holes or fix the grade and the second is to add nutrient back into the soil as part of your annual or regular lawn care program.
In many cases, people find themselves top dressing to correct poor preparation. Both a lack of quality under soil and poor levelling or laying can expedite the need to top dress. So if you’re just starting out in your lawn care journey, remember the 5 P’s – Proper preparation prevents poor performance. If you’ve taken your time during preparation, your lawn is well fertilised seasonally, healthy and level, then top dressing shouldn’t rarely be on your radar!
Sand Versus Soil
The product that will work best for you will really depend on your reasons for top dressing. There are many lawn enthusiasts out there that will exclusively dress their lawns with sand. Every spring, like clockwork a thin layer of washed sand will adorn their lawn and a few weeks later new green leaf growth will appear. Often, these enthusiasts are passionate (borderline fanatical) about their lawn and the process of top dressing is preceded by coring or aeration, scalping, de-thatching and accompanied by applications of fertilisers. This would combine into an annual lawn care regime to rival Royal Brisbane.
On its own sand will offer no nutritional benefit to your lawn or soil. But when strategically used to improve levels, drainage and soil structure, it can do wonders. However, top dressing year after year with only sand may cause the lawn to lose its fertility.
By far the best option for your average home greenskeeper is a top dressing soil blend. Top dressing soils are usually blends of finely screen top soil or loam, composts such as cow manure, and coarse sand. Quality mixes may contain added fertiliser for an extra kick.
Benefits of Sand
Using a sand such as USGA Certified Sand does have its benefits, particularly in the sports turf industries such as:
- Improved Smoothness – Voids exist within the turf canopy between turfgrass leaves and stems, causing inconsistent ball roll. Sand topdressing helps fill these voids to provide smoother and truer putts.
- Thatch Dilution – The layer of organic debris, stems, crowns and roots in the upper rootzone – i.e., thatch – can become concentrated and encourage mower scalping and localized dry spots. Thatch should be diluted with sand through practices like verticutting and sand topdressing to maintain good turf quality.
- Improved Turf Recovery – Occasional turf thinning can occur on putting greens. Sand helps cushion leaf tips and crowns and reduces algae.
- Increased Firmness – Turf produces organic matter in the upper rootzone that creates soft, spongy playing conditions. Regular sand topdressing, along with core aeration, improves surface firmness and resiliency.
- Improved Rootzone – Sand drains well and resists soil compaction. The accumulation of sand from multiple topdressings over many years can improve soil physical properties.
Benefits of Soil
A number of the benefits outlined above are also observed with the use of a quality top dressing soil mix particularly as many top dressing mixes are sandy loam based. When top dressing for nutrients, a thin layer of organic soil mixture over the area of your lawn will add organic matter, natural nutrients and minerals back into your soil, and continue to provide food for your lawn to draw on.
Which is right for you?
You would choose a top dressing soil if your lawn is in need of a boost as it will encourage the production of new shoots and result in a thicker lawn with the added benefit pest and weed resistance. You would chose a sand option when you need to fill holes, repair uneven ground, improve drainage and the soil structure. If you do decide to go down the sand route, it is recommended pairing a quality washed and sieved sand such as USGA Certified Sand with a quality lawn fertiliser to encourage fast growth and recovery. We recommend only top dressing with sand once or twice in the life of the lawn to make those improvements and incorporate a quality top dressing soil into your yearly routine moving forward.