Grass obtains three of the four essential factors (air, water, and nutrients) from the soil, but many soils are less than ideal for growing grass.
Most of our housing developments have very little top soil. When basements are dug, this dirt is placed on top of whatever good dirt was there. This is commonly referred to as "basement topsoil." To further compound the problem, a lot of equipment runs over the ground compacting the basement topsoil. As the soil particles are pushed together, air spaces are removed. This reduces the water holding ability and makes it harder for the roots to penetrate.
The value of proper site preparation and soil improvements, before any planting takes place, is that it will be easier for the grass roots to penetrate deeply and evenly. Deep roots will make the lawn more drought resistant and will allow for more efficient water and nutrient use from sub soil.
To give the plant an opportunity to grow and be healthy, follow these simple steps:
- Remove the weeds and debris
- Establish a rough grade to eliminate any drainage problems on the property
- Spread a minimum of 4 cubic yards of organics for every 1,000 sq. ft. of sod area
- Rototill 4 inches or deeper (if possible)
- Rake smooth and establish final grade
- Sub-grade 1 1/2 - 2" around curbs and sidewalks
By working up the soil, some of the compaction is relieved, creating more air spaces. Organics help in the water holding ability and provides some nutrients.
The site is now ready for sod. The extra efforts to prepare the soil will pay off in dividends. Excellent sod placed on poor site preparation doesn't look good. However, when excellent sod is placed on excellent site preparation, it results in an excellent job.
Sod really is as good as the base upon which it is installed.