CONSTRUCTION NOTES 2^3 



will not become buried too deeply in the soil, nor be lost because they are 

 not, on the other hand, covered enough to hold them in place until they 

 take root. Sometimes the surface layer of soil for a depth of an inch or 

 two is passed through a fine sieve or screen so as to ensure uniformity of 

 texture and size of particles, but this is seldom a practicable thing to do 

 except on small areas of special importance. Since the ideal soil for lawn 

 grasses is a loam it sometimes becomes necessary to modify the local soil, 

 if that is very sandy or clayey. Clay or silt may be added to sandy soils 

 up to about one-third of the total content in the top-foot layer. The clay 

 used for such purposes should be dry and crumbly so as to facilitate mixing 

 it with the sand. Humus material of some sort should also be added when- 

 ever possible. Sand and humus material may be added to stiff clay. From 

 one-quarter to one-third of the top foot of soil should be sand in this case, 

 and in either case a layer of humus-forming material three to four inches 

 deep should be plowed in or spaded in and thoroughly incorporated in the 

 top layer of soil. This humus material may be stable manure as mentioned 

 above or it may be some other material. 



Seeding seasons. Several factors govern the choice of seasons for seeding 

 lawns. More seed is required in late spring or summer on account of the 

 tendency of grass, which is started at that time, to grow tall and spindling 

 instead of forming shorter, stockier growth as in the fall or in the cooler 

 days of early spring. In addition to covering the ground more quickly, fall- 

 sown grass has fewer weeds to contend with at the start, since the period 

 of germination of annual weed seeds is over. Also, the heat of summer has 

 fallen to a point which still forces germination of the grass seeds without 

 burning up the plants. As a final factor, the soil moisture conditions are 

 quite likely to be more favorable in the fall, when seeding is delayed until 

 the fall rains start. In some portions of northern New York and New 

 England and in Minnesota, however, the severe winters are very hard on 

 newly sown grass, while spring sowing is favored in those regions by the 

 fact that severe hot weather seldom comes there before July, thus assuring 

 the grass a good start. From the middle of August to the middle of October, 

 depending upon the locality, is the preferred time for fall seeding, while 

 the latter part of March, all of April, and the greater portion of May form 

 the usual spring seeding season in the north. Patching may be done at 

 any convenient time when the ground is in proper condition. 



Seeding methods. The ideal time for seeding is toward evening on a 

 calm, dry day, because if the wind is blowing, an even distribution is prac- 

 tically impossible, and if the soil is wet it is likely to be sticky and pick up 

 in lumps on boots and rakes. A light, shallow raking should be given the 

 surface of the soil, and the seed should then be sown broadcast by hand. 



