The best seeds are produced from the lower part of the stalk, hence it is well to top the plant after the seed is well set, taking off about ten inches, and to remove the berries from the upper branches, that all the strength may go to the full development of the more desirable berries. If, after this has been done, there is more than sufficient seed for the purpose desired, a second discrimination can be made between the seed of plants which produce numerous berries and those which are shy bearers, the latter being desirable, as this indicates a tendency in the plant to produce stalk rather than seed, and it is as a stalk producer that asparagus is valuable.
Harvesting, cleaning, and preserving the seed is, of course, to be done carefully; the separation of the heavy and the light seeds can be accomplished by means of water, while the larger can be selected from the resultant mass by the use of a properly meshed sieve.
V
THE RAISING OF PLANTS
sparagus can be propagated by division of the roots, but this method gives so unsatisfactory results that it is rarely practiced. Raising the plants from seed is therefore the only method worth considering. The seed may be sown either in the fall or spring. But far more important than the time for sowing is the quality of the seed. While asparagus seed retains its vitality for two or more years, it is not safe to use seed older than one year. Fresh seed may be recognized by its glossy black color and uniform smooth surface, while old seed has a smutty gray color and its surface is generally rough and wrinkled. Yet even with this as a guide it is not easy to distinguish bad from good seed, and still more difficult, if not impossible, is it to distinguish the seed of different varieties. It is therefore advisable to procure seed only from dealers of undoubted reliability and pay a fair price for it rather than to accept poor seed as a gift. A uniformity of the individual plants in the asparagus bed or field is a matter of prime importance; only large, fully developed seeds should be used, screening out and rejecting all small and inferior ones.
In northern latitudes spring sowing is preferable to fall sowing. The ground of the seed-bed should be well drained and fairly retentive of moisture. As soon as the soil admits of working it should be well pulverized and enriched with decomposed manure. On a small scale a spading-fork is the best implement for preparing soil for nursery rows of asparagus plants.
Straight lines should be marked about fifteen inches apart and drills made about an inch deep when the sowing is done very early in the season, and one-half to one inch deeper when the sowing is done later. In these drills the seed should be dropped two or three inches apart. The covering may be made with a hoe, after which the soil should be well pressed down with the foot. As the seed is slow to germinate—in from four to six weeks, according to weather conditions—it is well to sow with it a few radish seeds, which will soon appear and mark the lines of the drills, so that cultivation may begin at once. Soaking the seed in luke-warm water for twenty-four hours before sowing will hasten its germination.