Slopes require special treatment as new seedlings on them are likely to be washed by heavy rains. You can use straw to cover them, but it must be picked up as soon as the grass gets started. Or the new seeding can be promptly covered with open mesh burlap or cheesecloth or a special garden supply stock of open mesh cloth that can be left in place to rot and become part of the soil.

This prevents soil erosion and keeps the soil surface moist, protecting the young seedlings from damage by exposure to the sun. Ordinary burlap should be removed when grass sprouts are 1/4 to 1/2 inch long.

Natural rainfall is best for new seeding, but if the weather is dry it is necessary to water for prompt germination. Do your watering in the morning, with a fine mistlike spray to avoid puddling or crust formation.

Once the seed has started to sprout, the moisture supply must be constant or the plants may die. For level places use a sprinkler and get the soil wet at least 5 inches with each watering, but don't keep watering until the soil is waterlogged and too compact. For slopes use a canvas hose, or wrap the hose in porous canvas, so that the water will ooze out slowly in big drops and go off into the soil quickly.

Seed mixtures in new plantings develop unevenly. The "nurse" grasses (such as rye grass), and the semi-permanent types will grow rapidly. To prevent their damaging the slower-starting permanent grasses, such as the bluegrasses, by their shade or competition for moisture and soil nutrients, begin mowing when the tallest grass is 2 inches. Do not mow shorter than 1½ inches.

Renovating Old Lawns

If you have been struggling in vain with a poor lawn, you might just as well do something drastic with it, such as spade it up and rebuild it. If you do, however, be careful not to build in the same mistakes again. If there are puddles or pools on your lawn for a long time after rain, you may need to lay drain tile or get a good layer of gravel under the topsoil. If your problem is due to a hard-baked soil and the grass is thin and anemic, spading up or plowing followed by soil preparation and reseeding, is probably the best procedure.

If limited areas (such as paths or low spots or areas around garden statuary) get too packed, they can be loosened and cultivated, or opened up by aerating to a depth of 6 or 8 inches. You can do this with an ordinary spading fork, driven deep and worked back and forth to enlarge the openings. Brush sharp sand or compost into the holes to attain better movement of air and moisture through the soil. Many poor lawns are due to poor soil conditions and can be improved by a better feeding program.

Use 4 pounds of plant food for each 100 square feet of lawn. If the grass is too thin, try plant food along with new seed. If your old lawn is bumpy, level it down, raking top-dressing into the hollows, or peel back the sod, filling in the hollow with good soil and replacing the sod. A mossy lawn is usually due to poor drainage, not to acidity in the soil (as is widely believed) and may need a change in grading for improved drainage, or raking and liberal fertilization.