Most lawn owners are struggling with forces beyond their knowledge. Many lawn experts talk over the heads of “Mr. and Mrs. Homeowner” who have not been trained in the ways of soils, plants, fertilizers, machinery and chemicals.
It does not seem feasible to develop a time-table for lawn management, because, Nature and water companies being what they are, one never can be quite sure of being able to stick to a pre-arranged program. “Across-the-hedge” advice always will be with us with its varying degrees of misinformation, but an understanding of why and how we do certain things to lawns will assure a greater chance for success.
A few facts about soils should be understood. Any resemblance between good soil and the stuff usually left by the contractor is strictly accidental and unintentional. Only a few contractors save the good topsoil to redistribute on the lawn area after the house is completed. Therefore, the majority of gardeners are forced to grow a lawn on the soil they have as money or good soil (or both) usually are not available.
Poor Soils Can Be Improved
Poor soils can be improved by periodic cultivation, aerifying or loosening. heavy liming and fertilization. Virtually all soils, sandy soils included, may become compact and crusted on top. Compaction and crusting are natural results of water and traffic. Crusted. hard soil prevents water from entering and the grass suffers because the water runs off. Fertilizer applied on such a soil can not enter, either, and may he washed away in a hard rain. Seeds which arc sown may germinate, but the tender roots cannot penetrate the crust, so seedlings perish. Oxygen, which roots need just as you and I, is prevented from entering the soil. The combined net effect is starvation, drought and suffocation, truly good reasons why so many lawns are poor.
Weeds come in and often are blamed for “crowding out” the grass. It just so happens that the weeds are better suited to the poor soil conditions. Change your conditions to suit the grass, and it will “crowd out” the weeds.
Changing Soil Conditions
What can you do to improve what you have? We are going to try to simplify lawn care and improve-meal and concentrate here on those practices which have the greatest possibilities of producing results.
First, we should improve the physical conditions of the soil. Every gardener knows the value of a mellow, loamy soil, well aerated for deep. healthy root growth which leads to more drought tolerance for the plant. In a lawn this desirable condition can be gradually accomplished by periodic cultivation and aeration (mechanical soil conditioning). The deeper, sturdier roots which grow as the result of cultivation and eventually die. add organic matter to the soil and help to create mellowness. The soil plugs or cores which are brought to the surface by aerifying help by top dressing the lawn. The alternate wetting and drying inside the spooned-out holes is one of Nature’s best ways of creating better physical soil conditions. Better air circulation in the soil greatly stimulates the unseen helpers – bacteria and other microorganisms – which by their growth and death improve the soil in many ways. The increased oxygen supply in the soil also stimulates root growth and helps the roots to absorb more nutrients.
Add Some Lime
In the humid, high-rainfall areas of the country, soils tend to become acid. Lime corrects acidity, makes nutrients more available, and produces a more mellow soil condition. Lime also granulates soils, which lets them breathe, and improves them for most plants – except acid-loving plants, which do not include grass. Home gardeners may choose between two forms of lime. The safest for all-round home use is ground limestone, also called pulverized limestone and agricultural limestone. This form of lime is usually cheaper, too. It does not burn the skin and it can be safely used with all fertilizers and seeds. Hydrated lime, although faster acting. is difficult to use. It will burn sensitive skin and must not be used with fertilizers because it releases nitrogen as ammonia gas which burns foliage.
Fall is a very good time to apply ground limestone. One bag (80 pounds) of limestone to 1000 square feet is a good application which need not be repeated for three to four years. To use too much lime, or apply it too often, is about as bad as not using enough. Aerifying before liming is recommended so that improvement of the soil can he made in depth instead of just at the surface. Lime moves downward in the soil very slowly. Experiments have shown that aerifying greatly improves penetration of slow-moving materials deeply into the root zone where they can do the most good.
Physical soil conditions can be improved further by mixing into the soil such amendments as peat, sawdust or sand – or a mixture of these. Too often these materials are spread on the surface of the lawn where they defeat the very purpose they are intended to serve. To be most effective they must be thoroughly mixed into the soil. There are two ways to do this: First, destroy the lawn, plow it or dig it up to mix the materials and start all over – mud, weeds and all. Second, spread the materials on the surface and mix by thoroughly aerifying which leaves the lawn intact without destroying the grass. This is the practice now being used on many golf courses while still maintaining excellent playing conditions. Obviously, the second choice is wiser because the lawn can be used continuously and it is much more economical. The most economical way, though, is to simply aerify, lime and fertilize and let the grass roots be the soil conditioner.
The next step toward a good lawn is to improve the nutrient supply. Most lawns are poor because they are starved. Well-fed grass will produce deeper, heavier roots which are Nature’s best soil conditioners. Therefore, indirectly, fertilizer acts as a soil conditioner by growing more organic matter. And, of course, it provides the elements necessary for healthy plant growth.
If you have either a compacted clay soil or a crusted sandy soil, fertilizer tends to lie on top of the soil where it has the best chance of being washed or blown away, and the least chance of getting down deeply into the, soil where the roots can get it. Aerifying to loosen and open the soil so that fertilizer can reach the roots is standard practice on most golf courses and on many athletic fields today.
How Much Fertilizer
What fertilizer should you use this fall? That question will be asked many times all over the country. There is understandable confusion because there are so many kinds available, ranging from the common everyday agricultural fertilizers to the highly advertised. special “Turf Fertilizers”. Soils differ as do the requirements of various turf grasses, so that there can be no “universal” turf fertilizer. For the lawn-owner the main features of a lawn fertilizer should be long-lasting effect, safety from burning, free-flowing and non-dusty texture. High-nitrogen content could be named a fifth point, because nitrogen is of the greatest importance in producing dense turf. Other nutrients (phosphorus and potash particularly) can he supplied by a single annual application of a complete fertilizer. Here arc a few examples of complete fertilizers to choose from, depending on your geographic location and available supply: 10-10-10. 12-12-12, 10-8-6, 10-6-4, 10-5-5, 8-6-4, 8-6-2, 7-7-7, 6-10-4, 5-10-10, 5-10-5, 4-12-4.
These fertilizers are best used once a year, either spring or fall, at a rate to supply one pound of nitrogen to 1000 square feet. Your dealer can give you the information on how much of a given fertilizer will supply one pound of nitrogen. You can figure it out for yourself, too. As an example, take a 10-6-4 fertilizer. The first figure is nitrogen. 100 divided by 10 equals 10. It takes 10 pounds of 10-6-4 to yield one pound of nitrogen. Another example is 5-10-10. The first figure is always nitrogen. 100 divided by 5 equals 20. It takes 20 pounds of 5-10-10 to yield one pound of nitrogen.
A lawn that has been fed 5-10-5 year after year probably suffers from acute nitrogen starvation and an overdose of phosphorous, the middle figure. The remedy for this is to use a straight nitrogen fertilizer for a couple of years at least. Organic nitrogen fertilizers are becoming more popular because they meet most of the requirements of a good lawn fertilizer. There are several kinds on the market, some derived from sewerage wastes and some derived from plant and animal by-products. The nitrogen content ranges from about 5 to 10 per cent. Monthly applications of organic nitrogen fertilizers, to yield one pound of nitrogen to 1000 square feet during the growing season, are becoming standard practice in some areas, particularly when the lawn contains one or more of the improved varieties of grasses.
A new long-lasting, non-burning type of nitrogen fertilizer has been developed by chemically combining urea and formaldehyde. Properly combined, the resultant product releases nitrogen slowly over a long period, similar in many respects to a natural organic material. One of these will be on the market this fall.
Fall Seeding and Reseeding
Competition is a word that applies to lawns as well as to the business world. In a starved lawn the individual grass plants compete for the available nutrients. Trees compete with grass (often unfairly) for sunlight, food and water. In a new seeding, young grass plants compete with each other – survival of the fittest. When rates of seeding are very high, the surviving plants may be so weakened that they cannot compete with the weeds. When fresh seed is sown on an established lawn. the new seedlings must compete with the grass that is already there. In many cases, a thin lawn can be thickened and improved by feeding, more easily and more economically than by reseeding.
One factor, more than any other, limits success in reseeding an old lawn. That factor is the seedbed. For instance, many lawns have been sodded with rough, weedy, ordinary pasture sod. There may be some good grass, but probably very little. Reseeding seems to he necessary. The usual practice is to scratch the soil with a steel rake. In theory, the advice may he good, but in practice it doesn’t produce results. The seed will germinate but the tender roots can not force their way through the dense crusted, compact soil. As a result, they die.
Aerifying, which is so beneficial for fertilizing and watering, is just as good for seeding. A seed which lodges in the loosened soil cavities is in the best possible position to germinate. It can send its roots down into the moist soil below and produce a sturdy plant which will add to the desired turf. It has been clearly demonstrated that with a proper seedbed, ‘ample nutrients and adequate moisture, less seed will be needed to produce desired results.
New seedings should be mowed as soon as there is anything to mow. Frequent mowing is important with any grass. The more often you mow an established turf, the better it will be, other things being equal. By all means remove the clippings. Accumulated grass clippings create ideal conditions for disease organisms and insects. The return of fertility from decaying grass cuttings is too small to be very significant on a lawn.
Water, if the water company can spare any for use on grass, should be applied generously at long intervals. Light. frequent sprinkling is a certain road to disaster. Good grass can wilt for several days without injury. When soil becomes dry, it releases more plant food with the next watering and it shrinks and cracks and lets air into the roots. Occasional drying is good for soil and grass. If the water runs off into the gutter, it is probably time to aerify again.
The basic principles of lawn management discussed here apply to practically all lawn grasses everywhere.
My final advice is to suggest that each reader call his county agent and ask for the latest circular or bulletin on lawns put out by the state college or university. Such a publication will contain complete local information that could not he developed in an article such as this. Requests for information on lawns gives real support to that phase of the university program and will assure you of better grasses and better lawns in the future.