LAWNS AND LAWN-MAKING 207 
bent grasses. Kainit may also be used as a source of 
potash. These fertilizers must be thoroughly worked 
into the soil while the ground is being prepared. Seed 
should not be sown for ten days or more after the appli- 
cationof strong commercial fertilizers in large quanti- 
ties, as the delicate seedlings are apt to be injured 
thereby. 
After thorough working and fertilizing, the sur- 
faces of the seed-bed must be put into exceedingly fine 
tilth for the reception of the seed. This is accom- 
plished by the aid of the acme and smoothing harrows, 
or, on small areas, the hand-rake and the roller. 
No effort should be spared to bring the surface to the 
desired tilth. A recent invention, the disk smoothing 
harrow, has proven very well adapted to the pur- 
pose. If the ground has been very deeply worked it 
may be well to let it settle a day or two before the 
final preparation of the surface. 
SEED AND SEEDING 
Only the best quality of seed should be used. It 
may cost much more than the cheaper grades, but is 
least expensive in the end. Cheap grades contain 
large quantities of chaff and offier inert matter, as well 
as the seeds of many kinds of noxious weeds. By 
actual weight weed seeds constitute from one to three 
per cent. of the average lawn grass-seed, while chaff 
makes up from twenty to fifty per cent., and even more. 
This inert matter does no harm when sown, but is 
expensive at the price paid for it as seed. 
The weight per bushel of the commercial grass- 
seeds varies with their quality. The standard or legal 
4 
