While the building is in course of construction the soil will become very much compacted by the teams and mechanics, a condition which is rather bad for the sustaining of grass. All the areas which have been trodden down hard should be loosened up before the surface soil is replaced. Better turf can usually be grown on soil that is broken up to some depth.
When the grading is being done it is well to take account of the nature of the soil and ascertain what treatment may be necessary for the production of a satisfactory stand of grass. If the soil is of a sandy or gravelly nature, or if it is lacking in humus, barnyard manure should be spread and thoroughly assimilated with the top soil. Should the soil be of a stiff, clayey nature, equal parts of sand and manure should be mixed through the top soil. This will make the soil more porous and the rain and air will reach the roots of the grass.
Another point to look to, at this time, is the digging and preparation of holes for any trees or specimen shrubs that it is planned to locate on the lawn. Such work can be done to much better advantage now than if left until after the rolling and seeding.
Sometimes it is necessary to raise the grade on ground where large trees are established. A fill of a foot or more of soil over the roots of most trees will kill them very quickly. Such trees may be preserved by building a dry retaining wall with a diameter at least two feet greater than the trunk. If the lawn is of sufficient size and the trees form a clump, a depression may be left around them.
The changed conditions make it necessary to provide new soil close to the house and on properties of small dimensions it may be necessary to resurface the entire area. Wherever fill is needed just as good soil as can be procured should be used and at least four inches of good top soil provided for the surface.
If the old turf needs remaking it should be dug or plowed to the depth of a spade, the soil being turned well over, stones and weed roots removed and large clods broken up.
Manuring or fertilizing is an important question. Experts claim that one ton of grass removes from the soil thirty-four pounds of nitrogen, thirty-six pounds of potash and seventeen pounds of phosphoric acid. It is largely these substances, therefore, that must be provided. Stable manure, if obtainable, is very satisfactory. Apply at the rate of one load per one hundred square yards and dig or fork it into the soil. Care should be exercised to see that the manure is not buried too deeply, else it will not be within reach of the new young grass - four inches is a good average depth. A good commercial fertilizer, containing four per cent, nitrogen, eight per cent, phosphoric acid and ten per cent, potash, will be found to give very satisfactory results. This should be applied at the rate of ten pounds per one hundred square yards and raked in. Fertilizers that are highly soluble should not be used on sandy soils, as they will quickly dissolve after rainfalls, be washed beyond the reach of the roots and so wasted. This same remark covers all commercial fertilizers applied in a wet season or a time of drought. In one case they are washed away, and in the other they lie about the surface and waste.
After manuring, the ground should be prepared to receive the seed. The soil should be carefully gone over with an iron toothed rake, all large stones removed, clods broken up and weed roots taken out, then rolled and raked until the surface becomes firm and fine; it should be so firm that walking over it leaves no footprints.
TREATMENT OF TERRACES.
Fig. 73. - This house is located on ground where the slope was so great that it was necessary to have a high terrace at one end, and run out to meet the natural grade at the other. It is always best to have a terrace as wide as practicable under such conditions, so that the end of the residence at the low point of the slope will have a more substantial setting. - See page 70.