A general rule is to sow in April and May; or September and October (See Plate III). It is but seldom that sowing in June or July is successful. If sown before the fall rains, grass should become sufficiently developed to withstand the winter weather. It is generally preferable to sow seed in the fall. If the soil is properly prepared in the fall, seed may be sown on a light fall of snow in the spring. The seed will sink in as the snow melts and will germinate very quickly. As a general rule a lawn seeded in the fall will develop to better advantage with less maintenance cost than a lawn seeded in the spring, because any weed seed present in the grass seed will germinate and most of the weeds will be destroyed during the winter months; while if the same seed is sown in the spring it is necessary to remove these weeds by pulling them before they go to seed. Seed should be sown at the rate of eighty pounds to one hundred pounds to the acre, or one quart to three hundred square feet. Always sow thick. Choose a day when the soil is moist, when there is little or no wind, and when the weather is comparatively cool. Seed is scattered broadcast by hand, and the hand must be kept low. Go over the area in narrow rectangular sections marked out, sowing one-half the seed; then repeat the process, walking at right angles to the previous course followed. After sowing, the ground should be raked lightly and rolled thoroughly. Very young grass must be safeguarded against drought by frequent and deep watering.
Wherever lawns are to be developed under large shade trees, such as maples, oaks, beeches, etc., great care should be used and the work of seeding should be completed at the earliest possible date in the fall.
It is not practicable to seed lawns late in the fall where large trees drop leaves which if not removed within one or two days are apt to smother the young grass. This is an important point to keep in mind.
The best grass generally for the foundation of a lawn, except on acid soil, is Kentucky blue grass. This does not fully mature until the third year. It is better, therefore, to use Kentucky blue grass in a mixture. Other grasses such as redtop and the creeping bents will produce a quicker effect and will keep out the weeds until the blue grass is fully established. Kentucky blue grass during the first year grows thinly, and continues to become thicker with successive mowings. When it is fully established it will crowd out some of the less permanent grasses in the mixture. The ideal lawn is one composed mostly of blue grass and it is also the most difficult to establish. Many people who wish to develop a good lawn in a short space of time resort to the use of a considerable portion of white clover. Clover is of no real value in the making of a fine lawn other than that it helps to produce a quick effect, thereby crowding out many early weeds, and that it produces a soft carpet effect with little difficulty, where the process of establishing a permanent lawn of blue grass might be slow.
The immediate development of a carpet of green over the surface of a lawn area is no indication that a permanent lawn has been established. The construction of a permanent lawn which requires only a normal expense in future maintenance involves not only the question of selection of grass seed of permanent types but also questions of adequate drainage, especially on heavy types of soil, and thorough preparation of the subsoil and the topsoil as a foundation of the lawn. Unfortunately many persons ignorant of the real requirements of a permanent lawn give much credit to those persons who are able, by the use of quick growing and temporary types of grass seed together with clover seed, and quick-acting fertilizers such as sheep manure (which soon releases all of its food value and leaves the lawn in an unfertile condition), to succeed in producing an immediate effect of greensward in a remarkably short time. The permanent and desirable types of grasses will not develop within such a short period, and lawns of this temporary character, while exceedingly satisfactory during the first year, will usually prove unsatisfactory and expensive in their maintenance cost during the succeeding years. Not only do certain types of grasses die out due to the nature of the grass and the lack of proper food supply but the lawn is seriously injured during the hot summer because of the shallow depth of topsoil that causes feeding roots to remain near the surface of the ground.
The various grass mixtures on the market vary in quality rather than in kind. It is inadvisable to buy poor seed. Many mixtures contain a large percentage of "chaff," and some mixtures contain more or less weed seed. It is highly desirable that any one responsible for the development of a good lawn should be able to identify the important types of good seed in lawn mixtures. Of the various grass seeds used the fescue and the clovers produce a quick effect during the first year.
The most common and satisfactory lawn seed mixture for the northern states is sixteen parts by weight of Kentucky blue grass, four parts of recleaned redtop, and one part of white clover. It should be used at the rate of one pound to each three hundred square feet of lawn or one hundred and twenty pounds per acre. The Kentucky blue grass is adapted to the northeastern states and the northwestern coast. It thrives on limy soil and will occasionally grow on land devoid of lime if the drainage is extra good. It makes a dense, vivid green turf except during midsummer when it is adversely affected by hot weather. It should not be confused with Canada blue grass which produces a tough but not dense or attractive turf and sometimes succeeds where the soil is too thin for Kentucky blue grass. Redtop succeeds under a very large range of soil conditions, from drought to wet land. It is one of the best grasses for poor soils throughout the whole of the eastern United States and thus succeeds where blue grass fails. It does not make a dense turf unless planted thickly and mowed closely. White clover as a turf plant succeeds on poor soils, forms a dense, close mat, and stands mowing well. If Kentucky blue grass is sown alone one hundred and fifty pounds per acre are required and liming is beneficial. If redtop is seeded alone forty pounds of fancy "recleaned" seed per acre are sufficient and no lime is needed. Clover is never sown in a clean stand but may be sown with or after grass seed at the rate of ten pounds of seed per acre.
For a fine turf similar to putting greens, useChewing's or New Zealand red fescue, which is a grass having a dark green colour and which makes a solid, compact turf. It is particularly adapted to sowing on sandy loam soil but succeeds well on clay loam or even on clays. When seeded alone one hundred pounds per acre should be used. It is the best lawn grass for growing in the shade under American conditions. Another fine-leaved grass making a dense, velvety turf is creeping bent. It does best where the summers are cool and moist; that is, in the northeastern states and on the northwest coast. When the soil is limy, other grasses, such as blue grass and white clover, tend to crowd out creeping bent. It should be sown alone except that combined with red fescue it will be satisfactory for a few years, after which the two grasses tend to separate and make circular mats.
There are standard mixtures on the market offered by the more reliable firms for special uses such as on golf greens, fairways, and shady locations.
In the section south of Washington, D. C, except in the higher altitudes, it is not advisable to use Kentucky blue grass. White clover, in this section of the country, becomes the prevailing grass in lawns. In the northern part of this area, white clover, redtop, and Rhode Island bent make an excellent lawn, but not a lawn as permanent in character as the northern turf.