The preparation process starts by carefully assessing your site to determine if the soil present is suitable for growing a healthy lawn. Most soils, even with above average clay content, will support a good lawn although amendments sometimes need to be added to allow adequate air to penetrate into the new lawn’s root system. In the case where heavy clay content does exist, it may be necessary to incorporate a layer of good topsoil into the existing soil to assure healthy growth. Be careful to select soil that is free of rocks, debris and weed rhizomes that may contaminate your lawn. Determine if you need to change the grade of your lawn. The lawn area should gently slope away from buildings to provide drainage.
If there are existing grass or weeds, spray the area with a non-selective herbicide such as Roundup or Finale (follow directions on label). Wait 7 days before working the soil. We recommend the addition of 4-6 inches of topsoil. The chart below gives a good idea of how far topsoil will cover. This would also be the ideal time to add lime since soils in Western Washington tend to be acidic (low pH). You may want to test the pH of your soil, but a good rule of thumb is to apply 40 – 50 pounds of lime per 1000 sq. ft. Then prepare the soil by tilling to a depth of 4-6 inches over the entire site to incorporate the topsoil and lime.
1 Cubic yard of topsoil will cover:
- inch deep = 324 sq. ft.
- inches deep = 162 sq. ft.
- inches deep = 108 sq. ft.
- inches deep = 81 sq. ft.
- inches deep = 54 sq. ft.
Next, grade your edges 1 inch below sidewalks, driveways and patios to provide a smooth transition onto the new turf. Also, look for low areas that may accumulate in excess water in the lawn, especially near the house. Either bring them up to grade by adding soil or provide a drainage basin to collect and transfer water out of the lawn. Smooth out the area by raking the high spots into the low areas. Remove rocks and debris as you rake. Establish a finish grade by “floating” (smoothing and leveling) the surface. Use a makeshift floating device such s a ladder or a 6″x6″ beam with rope tied to it and drag across the soil.
Roll the area with a water roller filled 1/3 full with water to firm up the soil. If you leave footprints of ½” or more when you walk across the soil, then you will need to roll the area. Then gently drag a large landscape rake over the area to slightly rough up the surface. The soil will accept the new turf best if the soil has a raked finish with a small amount of loose dirt on the surface (not a hard, rolled finish or loose, fluffy soil).