Any turf looks best if it is kept free from weeds. That is easily possible by the use of 2,4-D and any of the various crabgrass killers. Weeds are always less a problem under high mowing than if the lawn is scalped.

In the South, seeded grasses are fewer and have little varietal differentiation. Blending is practiced less than in the North. Bermuda, like bentgrass, is aggressive, and should have its own special management. It is usually sown by itself, planted in spring or summer, because it grows only in the warm season.

After bermuda goes dormant in autumn, some of the northern grasses may be intersown for color in winter. Annual ryegrass is used oftenest. As it dies the following spring, the bermuda can recover. Some lawnsmen are coming to the conclusion that other less competitive northern species, such as bluegrass, Poa trivialis, Poa annua, and fescue, offer less aggressive competition to the comeback of bermuda in the spring.

BLENDING of seeds, once done by hand, now often is mechanized. In automated operations of the larger companies, storage bins feed seeds directly into a weighing chamber and storage repository. In elaborate plants, appropriate controls can be set to introduce so much of several varieties. Each is checked for weight as it is introduced. The mixture is tumbled in rotating drums for complete mixing.

When the blend is ready for packaging, a worm screw in the center of the storage bin recirculates the seeds so that no differential sorting of types occurs as a result of their differing sizes, weights, or surface characteristics. Thus early and late packages from a blend lot will be identical.

In blending, the packager-seedsman has opportunity to exercise skills that may give him a better product and competitive advantage.

He has opportunity to produce or obtain from reliable sources the cleanest, fullest seeds.

Even though most seeds meet conventional marketing standards, as determined by purity and germination tests, subtle differences may occur, such as size of individual seeds, origin, kind of weeds, and proportion of chaff. Many packagers insist on standards above conventional specifications and pay a premium for such seeds. Beyond this, they may subject seed to a supplemental cleaning to remove the last traces of chaff and weeds. Such exceptionally clean, heavy seeds should give better performance in the lawn.

Skillful blending considers the use to which the turf will be put and the climate where the seeds are to be sold. A company has ample latitude to develop mixtures or blends it feels offer special advantages.

Most lawn seeds are packaged in units ranging from a few ounces to many pounds. Cardboard boxes constitute the usual package, but much is marketed in plastic sacks. As long as the seeds are not subjected to unduly high humidity or exceptionally warm temperatures, almost any packaging will keep seed satisfactorily. Most seeds endure well if the moisture content is low and temperatures are no higher than room level. Cold will not harm seeds; indeed, frozen seeds remain viable exceptionally well.

Every step of the way, lawn seeds must meet requirements of State and Federal laws. The laws were passed originally to regulate agricultural seeds at a time when lawn seeds were relatively unheard of. Consequently, some are questionable for example, many noxious weeds troublesome in agriculture do not persist in a mowed lawn. Standards for germination and purity, however, govern nongenetic qualities in lawn seeds the same as in agricultural applications. All seeds entering commerce are subject to the laws of the State in which they are sold and to the Federal Seed Act when shipped interstate.

Seeds in commerce are continuously sampled by control officials. They must be properly labeled or tagged to indicate weeds, germination, and purity. They must conform to State requirements as to weeds considered noxious in that State. Should the test samples not conform to label statements or requirements, a stop-sale order is issued, and the seeds are impounded. The purveyor may then be subject to civil proceedings. States have laboratories for checking samples, and many private laboratories analyze seeds on a fee basis.

BULK SALES from 100-pound sacks on the floor are becoming a thing of the past. Only packaged seed is available in many garden centers. This leads to vigorous merchandising and efforts toward brand identification on the whole, a good development in that it fixes responsibility more certainly. A list of ingredients, with germination percentages and weed content, must appear on the retail package.

If the customer will familiarize himself as to the preferable species for his climate, he can decide readily the quality of a purchase. He will be less apt to buy lawn seed by price and buy according to what is in the package.

Research departments of major seed-houses and industry groups provide reliable instructions for use of their products. Their stall's keep abreast of the research nationally and interpret findings for public benefit. The hope is that the public will be induced to choose its grasses ever more wisely.

THIS EVER-GROWING responsibility of the seed industry to gather and disseminate sound information is recognized by many.

There also is a trend toward horizontal integration. So many products that affect the performance of a seeding are introduced each year that a seed company cannot risk ignorance of herbicides, insecticides, fertilizers, soil amendments, sprinklers, mowers, applicators, and a host of other items.

The realization is growing that one who plants seeds is less interested in seeds as such than in the hoped-for outcome of planting the seeds a good lawn. A good lawn will result only from good seeds that are treated correctly. That means that one must have information about correct fertilization, watering, mowing, and so on if users of seeds are to be satisfied.

Many seedsmen therefore have become well-rounded experts, who have learned a great deal about the chemicals and equipment that can help good seed become good turf.

ROBERT W. SCHERY is director of the Lawn Institute, Marysville, Ohio. He is a native of Missouri and was educated at Washington University, from which he holds a doctorate. He is the coeditor and coauthor of The Flora of Panama and the author of two books, Plants for Man and The Lawn Book.