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- 

 cation of 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 other inert matter, as well 

 as the seeds of many kinds of noxious weeds. By 

 adlual 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 



