The key to success in laying a lawn is careful soil preparation. If soil conditions vary a lot, the lawn will not be uniform, therefore, take some time over soil preparation. Prepare for spring sowing during the previous autumn and winter, and for autumn sowing during the summer.
Lawn meets garden woodland
A weed-free start is essential. Use Tumbleweed or Roundup to control existing grasses and weeds, including perennial weeds. If the weed cover is heavy, a second application might be needed. Level the surface after the initial weedkiller application. Then wait four to six weeks and spray again. Rake the surface and wait again before applying another spray of Roundup or Tumbleweed.
Waiting and repeat spraying is known as the ‘stale seed bed’ technique and it is a way of getting rid of wild grasses and weed seeds that are in the top few centimetres of soil. It is not essential to go to these lengths in preparation but this approach ensures a clean start for the lawn grasses and avoids contamination with wild grasses. While it is possible to control broad-leaved weeds after sowing, there is no easy way of controlling wild grasses.
Large stones, old tree roots and other rubbish should be removed. Level the humps and fill in the hollows before cultivating or adding extra top-soil. This helps to ensure an even depth of good top-soil. Dig the ground with a spade or use a rotavator if the area is large. Allow the soil settle for at least eight weeks to avoid settling later when bumps and hollows will form. Rake over the area when it has settled and move soil around to fill hollows. The ‘stale seedbed’ technique allows the time for settling to take place ove a large area.
On small areas, it is possible to tread the area when dry to firm the soil and break up lumps. Rake over the area to even out small bumps and hollows. Work in some moss peat at the rate of one giant bale per 13–18 square metres. Work this into the top 5 centimetres during subsequent raking. The peat will give body to sandy soils and help to open the surface of heavy soils.
Continue to rake the ground at intervals of three weeks or so. Suspend operations during the months when the soil is wet. Serious compaction can result from walking over wet soil. Repeated raking levels the ground, settles it, makes it fine and controls small weed seedlings. If a flush of weed seedlings gets a start, use Weedol or Basta to burn them off before they get too big.
Apply general fertiliser at 100 grams per square metres about a fortnight before sowing is planned and rake it in. At that stage, stones more than 2 centimetres across should have been removed the top 2-3 centimetres of soil. These can cause problems with lawn-mowing later and the ground should be raked over until they are removed.