One of nature’s beneficences is the resurgent growth of grass in late summer and autumn when nights become cool and the soil gathers more moisture. This is the most opportune time for making or renovating the lawn. Weeds are less active, too.
Perhaps two of the greatest obstacles to a successful lawn are weeds and compaction of the soil. Walked upon continually, often rolled when wet and subjected to the packing effect of heavy mowers, the lawn surface tends to consolidate; air is shut off and the roots starve “in the midst of plenty.” For no matter what fertilizer is applied, if air is lacking at the roots the food cannot be used. In this sense, a compact soil is a poor soil. That grass grows abundantly in a well aerated soil is good proof that it needs air. And, ironically, the very conditions that are unfavorable to grass seem to stimulate weeds.
There’s a reason for this. Grass roots are annualÑthat is, each year grass makes a new set of roots near the surface. Lawn weeds have perennial roots. But more than this, they have a faculty grass does not possess: they can extract the very nutrients they need from even a poor soil and from the decaying roots of the grass itself. No wonder they are so hard to eradicate! A piece of root left in the soil when the weed is pulled out starts a new crop.
The present condition of your lawn will determine the program to follow. An old thin sod, especially if it is weedy, , is better dug up and a new lawn begun. In many cases, however, a top-dressing of some sort will suffice. This would suit a lawn made last spring which has not become well established before summer. The lawn with 60 per cent good grass can be renovated hy top renewal.
But the first step in any lawn program must be elimination of weeds. Chemicals are the best means here. The weed leaves absorb the applied chemical, which upon entering the sap stream is carried to all parts of the plant. If a strong application is made, only the weed tops may be killed since the chemical may destroy the vessels that could carry it to the roots. Of course, if the soil is also saturated, the roots will -absorb enough directly to kill them. However, it is best to study and follow the manufacturer’s directions. Best results are obtained during active growth. When weeds reach the seed-forming stage the results are less certain.
Crabgrass will start forming seeds towards late August. One of the chemicals used to control this weed should be applied now.
If the lawn is in pretty good shape, a little patching of weed spots with seed and topsoil, plus an application of a fertilizer like 10-8-6 (20 pounds per 1.000 square feet) will suffice. Often times a more extended operation is needed. Top-dressing is not made on the average lawn as a general practice, but many a good Iuwn has thus been built.
If weeds have been removed there will be many holes and a much-pitted surface. Grade these spots as evenly as possible with a rake. Then apply a top-dresslil’.1. The ideal top-dressing is made by mixing together two parts of loam topsoil. one part coarse (not fine) sand, one part peatmoss and humus, half and half. To get a weed-free mixture, add 13 pounds of cyanamid to each cubic yard of soil.
Before the top-dressing is applied, the area should be perforated with a digging fork or with a tool devised for aerating , the soil. The top-dressing is then worked in with the back of a rake.
When it complete fawn must be made. the area is dug over to a 12-inch depth, if possible, or worked with a rotary tiller. If the soil is heavy, work in a 4-inch covering of coarse sand or screened coal ashes to improve the porosity. For organic matter, use decomposed compost or a mixture of peatmoss and commercial humus. A 1-inch depth of either conditioner will improve the poorest of soils. To secure a weed-free soil, apply cyanamid to the surface at the rate of 50 pounds per 1,000 square feet and work into the top 3 inches. The surface is then roiled and allowed to remain unplanted for four to five weeks.
Use a seed mixture which is suited to your soil and your region. The better seed houses have mixtures for all kinds of soil and sitesÑsand, clay and looms, and for sunny sites and terraces. Be specific about your conditions when ordering the seed. Four pounds of seed per 1 1,000 square feet of lawn (two pounds for renovation) will be ample. Split the quantity in half and sow one half at right angles to the other for even distribution, Choose a still day to sow the seed and cover it by raking. Then roll the area to get the seed in close contact with the soil.
Soil should be moist as well as properly prepared if the conditions for seed germination are to he ideal. If the soil is very dry, defer seeding until after a rain, unless it is possible to water the area heavily and wait a day or two before sowing the seed.
