Proper Soil Preparation
Whether choosing to seed or sod, success will depend on good soil preparation. If this step is done properly, the lawn will provide years of satisfaction. If this step is neglected, it will be more costly and less convenient to correct any underlying soil problems once the lawn has been installed and established.
Guidelines to Avoid Common Site and Soil Preparation Pitfalls
- Remove existing perennial broadleaf weeds and grasses. Examples of broadleaf weeds include: dandelions, thistles, plantain, and clover. Examples of perennial weedy grasses include quackgrass and orchardgrass. Leaving existing perennial weeds and grasses only invites weed problems in the newly establishing lawn.
- Test the soil and add the necessary potassium or phosphorous by rototilling it into the top 4 to 6 inches. If topsoil is added, don't assume that it is rich in nutrients, regardless of its color. Test it and make any nutrient additions that are necessary. Topsoil should be of a sandy loam texture with a good black color. Avoid heavy muck soils sometimes offered as topsoil.
- If topsoil or peat is added, rototill it into the upper 4 to 6 inches. This step can be combined with the fertilizing step just described. For sandy or clay-like soil, spread 12 to 18 cubic feet of baled peat moss per 1,000 square feet (the equivalent of a depth of 2 to 3 inches spread over 1000 square feet). However, it should be noted that sandy soils are excellent for growing grass without the need for peat additions IF consistent irrigation and nutrients can be supplied. Topsoil should be added at a rate of 3 to 4 cubic yards per 1,000 square feet (the equivalent of a depth of 1.5 to 2 inches spread over 1000 square feet). Likewise this should be rototilled into the existing upper 4 to 6 inches of soil.
- A good quality compost can be used as a soil amendment in place of topsoil or peatmoss. Compost is often times a preferred choice due to the fact that it is derived from otherwise 'waste' material as opposed to being harvested as is the case with peat moss. Compost should be added at a rate of 2 to 3 cubic yards per 1,000 square feet (the equivalent of a depth of 1 inch spread over 1000 square feet) and rototilled into the existing upper 4 to 6 inches of soil. For more on compost see:
- Don't be talked out of proper soil preparation if topsoil, peat moss or compost is added. Leveling with a grader blade is not a substitute for rototilling. Likewise, simply applying a thin layer of 'topsoil' on top of an existing soil without incorporation into that existing soil is not a good idea either. Separate, distinct soil layers each with their own water infiltration and movement characteristics make water movement into and through the soil difficult. This can create shallow rooted turfgrass and soil conditions that can remain too wet or too dry.
- Rototilling under trees will disrupt their feeder roots and may cause considerable damage. Use a vertical mower to scratch the soil surface when preparing the area beneath trees. This is a better method of soil preparation than rototilling or other form of deep cultivation.
- Don't pack the soil too firmly before seeding or sodding; use a garden rake to level uneven areas. Be sure to re-firm and level the soil after rototilling to create a uniform, stable soil surface. Proper soil firmness can be gauged by walking across the soil surface - the surface should feel firm and your shoes should sink in no more than ½ inch.
Proceed to Establishment by Seed.