Summer Grasses.—One of the worst pests is the annual grasses, springing up in June, July, and August. They are responsible for many failures to obtain stands of alfalfa, clover, and the valuable grasses. The delay in seeding until August is due largely to this pest. When seedings are made in the spring, or in June, failure is invited where these grasses have a fast hold. The only effective way of combating them is to make the ground firm enough to encourage germination, and to stir the surface whenever a growth starts. The late seeding is the one means of escape, and if there is fertility and moisture, the newly seeded crop becomes well rooted by winter and takes the ground so completely that there is little room for weeds to start the next year.
Sowing the Seed.—Partial failure with August seeding is due to faulty methods. We are accustomed to broadcasting clover seed on top of the wheat fields and obtaining a stand of plants. A majority of the seeds do not become buried in the soil, or only very slightly, and yet germinate. Moisture is necessary, but in the spring, when this method is used, there is moisture at the surface of the ground under the wheat plants much of the time. The conditions respecting moisture are not unfavorable in most springs, and we come to think that a small seed should not be buried much if any. In the autumn, again, we sow timothy with the wheat, and while more prompt germination is secured by covering the timothy seed with the hoes of the drill, we often have seen a successful seeding made without any covering being given. The work is done at a time when fall rains may continue for days and, when the sun's heat does not continue long, the covering given by settling the seed into the loose earth is sufficient. Moisture does not leave rapidly because the air is not hot.
Deep Covering.—In August the air is hot, and the surface of the ground is dry nearly all the time. A shower may be followed by hot sunshine, and the water at the surface evaporates quickly, leaving the ground covered with a dry crust. There are two essential things to bear in mind: the seeding should be made only when there is enough moisture in the ground to insure quick germination, and preferably as soon as feasible after a rain, and the seed should be put down where moisture can be retained. It is poor practice to sow any kind of small seeds before a rain that seems imminent. If it forms a crust, or causes weed-seed germination along with that of the grass seeds, only harm results. When seeds are put into a dry soil, and a light shower comes, there may be germination without sufficient moisture to continue life in the plants.
The seeds should be well buried: the soil and air conditions are different from those of the spring. It is best to wait for moisture, and to save the seed if it does not come, but when enough water has fallen to make the firm soil moist, the danger of failure is very small if the seeds are buried one to two inches deep. A surface harrow will stir the surface, and then the seeds should be sifted down into the soil by another harrowing. A light plank float, mashing the little clods and pressing the soil slightly together, finishes the work. The plants will appear above ground within a few days, the only danger being in a beating shower that may puddle the surface before the plants are up.
Seed-mixtures.—When grass is wanted for hay as well as fertility, the clovers and timothy compose the greater part of a desirable mixture wherever the clovers and timothy thrive. Probably this condition always will continue. The clovers are needed to supply nitrogen to the soil and to put protein into the hay for livestock. They give way, in large part, or entirely, the second year. Alsike is more nearly perennial than the red which practically lasts only through its second season, when its seed crop has been made, and its function performed. The sod is chiefly timothy in the second season. A little red-top is desirable, and the percentage should be heaviest for quite wet land or very dry land. When fertility is the first consideration, and the sod is left only two or three years, the following mixture is good, and is for one acre:
| Red clover | 10 pounds |
| Alsike | 2 pounds |
| Timothy | 8 pounds |
| Red-top | 2 pounds |
When a mixed hay is wanted the first year, the following mixture may be found better for the purpose:
| Red clover | 6 pounds |
| Alsike | 2 pounds |
| Timothy | 12 pounds |
| Red-top | 2 pounds |
Mammoth clover seed may be substituted for the red without change in number of pounds.
The amount of timothy and red-top in the second mixture suggested calls for a liberal supply of plant-food, and this is true of any heavy grass mixture. If fertility is not present, the seeding of grass should be lighter, but the clover should not be less in amount for a thin soil than for a good one. The question of fertilizers is discussed in Chapter XX.