The keynote of success in securing a good lawn is thorough preparation of the area before seeding. Failures are almost invariably due to poor preparation rather than to poor seed. Grading should be finished with a view to seeding either in the early fall or spring. Prepare the soil thoroughly, for the permanence of the sod rests entirely on this initial outlay. The soil should be deep and porous to produce deep rooting of the turf, which means success in combating winter-killing and drought. For the ideal lawn the ground must be prepared to a depth of one foot; but eighteen inches is preferable. If the area is large enough it should be plowed; otherwise spading must be resorted to. When the soil is naturally good and there is ample topsoil (six inches to eight inches) deep plowing without subsoil-ing is sufficient. In heavy soils the clay subsoil should be broken up but not brought to the surface. After plowing, if the area is large enough to permit the use of a team, the soil should be worked fine by harrowing. Follow this operation by levelling with shovels and hoes, and finally with rakes. The top layer of soil should be made very fine to induce quick germination of seed and permanency of sod.
The average lawn to which the author refers is the lawn developed in the immediate vicinity of the residence. If building operations have extended over the greater portion of this lawn area, as is general on the smaller residence lots, then all of the topsoil should have been stripped and placed in one or more large piles prior to the commencement of any building operations. In the preparation of a lawn area under such conditions it is very advisable to delay actual work upon this area until after that portion of the building operations apt to cause further litter to be thrown over the lawn area is completed. While the ideal lawn area should have a proper depth of topsoil in which the feeding roots of grass can develop, there are many instances where for purposes of economy or otherwise a sufficient depth of topsoil is not provided.
The first step is to determine the depth of topsoil which is to be finally spread over the finished subgrade of the lawn. The less the depth of topsoil the greater will be the cost of future maintenance over a period of years succeeding the first year. The surface of the finished subgrade should be established to conform with the finished grade of the lawn area and at a definite, even depth below this finished grade of this lawn area. No topsoil should be spread over this subgrade until every precaution has been taken to be certain that an excessive depth of topsoil will not be necessary where spots of extreme depression can be located in the surface of the subgrade and previously filled. In sections of the country where the subsoil consists of a clay loam and other types of heavy soil the item of providing topsoil for the preparation of the lawn area is one of the most expensive items in the landscape development of the property. Experience has shown that topsoil is one of the items which is often subjected to the greatest amount of waste, and it should be carefully conserved and not used, in any instance, except to the correct depth as required.
When the subgrade is completed and previous to the application of any topsoil it is often well, especially on types of clay soil, to apply a coating of lime at the rate of not more than twenty-five pounds to every 1,000 square feet. On the top of this, a layer of well-rotted manure at the rate of one cubic yard for every five hundred square feet should be applied. The lime and manure should then be spaded or harrowed into this finished surface of the subgrade and the final surface smoothed with shovels or rakes before the final layer of topsoil is applied. This thorough preparation of the subgrade is much more essential if a shallow depth (two inches to three inches of topsoil) is to be used. It is not so essential if a more generous depth (four inches to six inches of topsoil) is to be used.