Over the years we have worked in this environment several lessons have made themselves clear, and one very important one is that planting lawns on soil has some serious drawbacks. One is that good well drained soil is often difficult to come by, most soil offered for sale is screened silt, some with a mixture of sand or organics to make it darker and appear more valuable and any offered is often filled with tenacious weed seed.
Soil based lawns seem to battle moss from day one, and in the case of lawns meant as play areas, running feet turn lawns to mud in our often rainy summers.
We were looking for a lawn that would grow quickly, be able to compete with moss, and tolerate foot traffic Casting about for solutions we observed that grass seemed to grow well in sand, and as we investigated we found that the original clone of “Nugget” Bluegrass, our favorite lawn grass had been discovered growing on the beach at Nome.
We began experimenting and developed a protocol for a sand based lawn for our climate. We used washed concrete grade sand, no fine particles, laid down in 4-6 inch depth. This was pretty easy to find, since the criteria for concrete sand allows no silt or clay.
Sand is spread, raked and rolled or compacted to make sure it is uniform and will not settle unevenly. We then spread 6 bales of packaged peat moss per 1000 square feet, and rake it into the top 2 inches of the sand. This will help hold the water and nutrients as the grass begins to grow.
Then we relevel it, and re-compact it, on top of the sand layer we follow this regimen, all measurements are per 1000 square feet:
- 40 lb Dolomite Lime
- 20 lb 16-16-16 fertilizer
- 4 lb Bluegrass
- or 5 lb of a custom mix of grass varieties including 30 % by seed number of Bluegrass, “Boreal” Creeping Red Fescue and a modern hybrid Perennial Ryegrass, and 10% annual Ryegrass
this is then topped with ¼ inch of peat moss and carefully watered for the first time, avoiding washing anything around.
The Bluegrass germinates in 28-30 days, but the mix has some quick germinating Annual Rye that comes up in a week, so any large gaps can be seen quickly and reseeded.
Since we are growing on sand, and it dries out more quickly than dirt, attention must be paid to keep the seed bed moist during the whole time period, until all the varieties of grass have germinated.
At 30 days after seeding we apply a liquid fertilizer at half strength, and then at 60 days, after the first mowing, we do it again, thereafter we fertilize regularly, full strength, with a nitrogen fertilizer, using no more phosphorus.
And since the grass roots will have to knit the sand together we do not mow for 60 days after seeding.
Hold off allowing dogs on the area for the first season, they can really dig up the sand, but after the first season it is ready for soccer playing, tractor driving and high speed mowing, but do not abandon the regular fertilizing.