Loose and deep soil, free from clods, is required to grow straight and well-developed roots. The land must also be perfectly drained, not only to remove superfluous moisture, but to provide a deep and friable soil. Subsoiling is useful in hard lands. A large admixture of sand is generally desirable, provided the soil is not likely to overheat in sunny weather.
To keep roots fresh in the cellar, pack them in barrels, boxes, or bins of sand which is just naturally moist, allowing each root to come wholly or partly in contact with the sand. The best material in which to pack them is sphagnum moss, the same that nurserymen use in packing trees for shipment, and which may be obtained in bogs in many parts of the country. In either sand or sphagnum, the roots will not shrivel; but if the cellar is warm, they may start to grow. Roots can also be buried, after the manner of potatoes.
Alliaceous group—Onion, leek, garlic.
A group of very hardy cool-weather plants, demanding unusually careful preparation of the surface soil to receive the seeds and to set the young plants going. They withstand frost and cool weather, and may be sown very early. Seeds are sown directly where the plants are to stand. For early onions, however, the special practice has recently arisen of transplanting from seedbeds.
Brassicaceous group—Cabbage, kale, cauliflower.
These are cool-weather crops, all of them withstanding considerable frost. The cabbages and kales are often started in fall in the middle and southern latitudes, and are harvested before hot weather arrives.
In the northern states, these plants will all do best when started early in hotbed, frame, or greenhouse,—from the last of February to April—and transplanted to the open ground May first to June first, partly because their season of growth may be long and partly to enable them to escape the heat of midsummer. Still, some persons are successful in growing late cabbage, kale, and cauliflower, by sowing the seeds in hills and in the open ground where the plants are to mature. It is best to transplant the young plantlets twice, first from the seed-bed to boxes, or frames, about the time the second set of true leaves appears, placing the plants 24 inches apart each way, and transplanting again to the open ground in rows 4 to 5 feet apart, with plants 2 to 4 feet apart in the row. If the plants are started under cover, they should be hardened off by exposure to light and air during the warmer hours of several days preceding the final transplanting.
The most serious enemy of cabbage-like plants is the root-maggot. See discussion of this insect on pp. 187, 201.
The cabbage-worm (larva of the white butterfly shown in Fig. 295) can be dispatched with pyrethrum or kerosene emulsion. It must be treated very early, before the worm gets far into the head (p. 200).