When raised in cold frames in the spring, the seed should be planted about the first of April, mats being used to retain by night the solar heat accumulated during the day. As the season advances the same process of hardening will be necessary as with those raised in hot-beds.
COLD FRAME AND HOT-BED.
To carry on hot-beds on a large scale successfully is almost an art in itself, and for fuller details I will refer my readers to works on gardening. Early plants, in a small way, may be raised in flower pots or boxes in a warm kitchen window. It is best, if practicable, to have but one plant in each pot, that they may grow short and stocky. If the seed are not planted earlier than April, for out-of-door cultivation, a cold frame will answer.
For a cold frame select the locality in the fall, choosing a warm location on a southern slope, protected by a fence or building on the north and north-west. Set posts in the ground, nail two boards to these parallel to each other, one about a foot in height, and the other towards the south about four inches narrower; this will give the sashes resting on them the right slope to shed the rain and receive as much heat as possible from the sun. Have these boards at a distance apart equal to the length of the sash, which may be any common window sash for a small bed, while three and a half feet is the length of a common gardener's sash. If common window sash is used cut channels in the cross-bars to let the water run off. Dig the ground thoroughly (it is best to cover it in the fall with litter, to keep the frost out) and rake out all stones or clods; then slide in the sash and let it remain closed for three or four days, that the soil may be warmed by the sun's rays. The two end boards and the bottom board should rise as high as the sash, to prevent the heat escaping, and the bottom board of a small frame should have a strip nailed inside to rest the sash on. Next rake in, thoroughly, guano, or phosphate, or finely pulverized hen manure, and plant in rows four to six inches apart. As the season advances raise the sashes an inch or two, in the middle of the day, and water freely, at evening, with water that is nearly of the temperature of the earth in the frame. As the heat of the season increases whitewash the glass, and keep them more and more open until just before the plants are set in open ground, then allow the glass to remain entirely off, both day and night, unless there should be a cold rain. This will harden them so that they will not be apt to be injured by the cabbage beetle, as well as chilled and put back by the change. Should the plants be getting too large before the season for transplanting, they should be checked by root pruning,—drawing a sharp knife within a couple of inches of the stalk. If it is desirable still further to check their growth, or harden them, transplant into another cold frame, allowing each plant double the distance it before occupied.
The structure and management of a hot-bed is much the same as that of a cold frame, with the exception that the sashes are usually longer and the back and front somewhat higher; being started earlier the requisite temperature has to be kept up by artificial means, fermenting manure being relied upon for the purpose; and the loss of this heat has to be checked more carefully by straw matting, and, in the far North, by shutters also. In constructing it, horse-manure, with plenty of litter, and about a quarter its bulk in leaves, if attainable, all having been well mixed together, is thrown into a pile, and left for a few days until steam escapes, when the mass is again thrown over and left for two or three days more, after which it is thrown into the pit (or it may be placed directly on the surface) which is lined with boards, from eighteen inches to two feet in depth, when it is beaten down with a fork and trodden well together. The sashes are now put on and kept there until heat is developed. The first intense heat must be allowed to pass off, which will be in about three days after the high temperature is reached. Now throw on six or eight inches of fine soil, in which mix well rotted manure, free from all straw, or rake in, thoroughly, superphosphate, or guano, at the rate of two thousand pounds to the acre, and plant the seed as in cold frame. Harden the plants as directed in preceding paragraph.
CAULIFLOWER, BROCCOLI, BRUSSELS-SPROUTS, KALE, AND SEA-KALE.
My treatise on the cabbage would hardly be complete without some allusion to such prominent members of the Brassica family as the cauliflower, broccoli, brussels-sprouts, and kale.
Cauliflower. Wrote the great Dr. Johnson: "Of all the flowers of the garden, give me the cauliflower." Whether from this we are to infer the surpassing excellence of this member of the Brassica family, or that the distinguished lexicographer meant emphatically to state his preference of utility to beauty (perhaps our own Ben. Franklin took a leaf from him), each reader must be his own judge; but be that as it may, it remains true, beyond all controversy, that the cauliflower, in toothsome excellence, stands at the head of the great family of which it is a member. To be successful, and raise choice cauliflowers, is the height of the ambition of the market gardener; and, with all his experience, and with every facility at hand, he does not expect full success oftener than three years in four. The cauliflower, like the strawberry, is exceedingly sensitive to the presence or absence of sufficient water, and success or failure with the crop may turn on its having a full supply from the time they are half grown. The finest specimens raised in Europe are grown in beds, which are kept well watered from the supply which runs between them; and the most successful growers in the country irrigate their crops during periods of drouth. Cauliflowers do best on deep, rich, rather moist soils. In the way of food, they want the very best, and plenty of it at that. The successful competitor, who won the first prize at the great Bay State Fair, to the disgusted surprise of a grower justly famous for his almost uniform success in winning the laurels, whispered in my ear his secret: "R. manures very heavily in the spring for his crop. I manure very heavily both fall and spring." In manuring, therefore, do as well by them as by your heaviest crop of large drumhead cabbage, using rich and well-rotted manure, broadcast, with dissolved bone or ashes, or both, in the drill. Plough deep, and work the land very thoroughly, two ploughings, with a harrowing between, are better than one. Give plenty of room; three by three for the smaller sorts, and three by three and a half for the later and larger. They need the same cultivation, and, being subject to the same diseases and injury from insect enemies, need the same protection as their cousins of the cabbage tribe. In raising for the summer market, start in the cold frame, or plant as early as the ground can be worked, that the plants may get well started before the dry season, or the crop will be likely to make such small heads "buttons" as to be practically a failure. For late crop, plant seed in the hills where they are to grow, from the 20th of May to the middle of June. The crop ripens somewhat irregularly. When there is danger from frost, the later heads should be pulled and stored, with both roots and leaves, being crowded, standing as they grew, into a cold cellar or cold pit, when they will continue growing. As soon as the heads begin to form, they should be protected from sunlight by either half breaking off the outer leaves and bending them over them, or by gathering these leaves loosely together and confining them loosely by rough pegs, or by tying them together with a wisp of rye-straw.