About the 20th of February is early enough, in this latitude, to gather and prepare materials for the hot-bed. Fresh stable manure alone may be used, though preference is generally given to a mixture, in equal proportions, of manure and forest leaves. Place on the ground, (under a shed if possible,) a layer of leaves one foot thick, and on this a foot of manure, then leaves and manure alternately until the required quantity is obtained. Let this heap remain four or five days, or until it begins to heat, then turn over and thoroughly mix the leaves and manure together, and throw them up into a compact, conical heap. In four or five days more your materials will be ready for your bed. Mark off your intended site, running as nearly east and west as practicable. Your frame should be about six feet wide and of any required length. The manure bed should extend a foot outside the frame on the sides and ends. See Figure 1, in which a is the manure heap.
Fig. 1.
Build up the manure square and level, shaking, mixing, and beating it with the back of the fork, to the height of about four feet, making the centre somewhat higher than the sides, to allow for settling. The frame should be of 1-1/4 inch pine, twenty inches high at the back, and seventeen inches in front, and may be put together with hooks and staples, so as to be removed and stored, when not in use. The sashes should be six by three and a half feet, and the frame should have cross-bars at every sash for support. It is well to have the frame divided by partitions into two or three compartments, that one section may receive more or less ventilation as the plants grown in them may require. In three or four days the heat will be up in the bed, and then it should be covered with six inches of fine garden mould, which should be raked off level. When the soil is heated through, the seeds may be sown. Ventilation should be given to let off the steam and vitiated air, but with caution to avoid the loss of heat. Straw mats will be required to cover the sashes at night, and should be regularly put on. If the weather is very cold, shutters or boards in addition are necessary. If care is exercised in the management, the heat will be maintained as long as is desirable.
Figure 2 represents the hot-bed partly beneath the surface.
The frame in this case will be fifteen inches in height at the back, and twelve inches in front, constructed in the same manner as that before described. The materials and the general preparation of the bed is also the same. A space of about eight inches should be left between the surface of the mould and the glass, to allow for the growth of plants before the sashes can be removed. Coarse litter should be put around the frame, and up even with the top of it, to confine the heat. Beds should be well covered before the sun has left them in the afternoon, and not opened in the morning until the sun is well up. Seeds of vegetables for early planting, and those of annual flowers may be sown, and cuttings of green-house and bedding plants started in pots. Such a bed will also be a favorable place for the propagation of grape eyes, in which an experienced person will often succeed better by this humble means, than with the best designed and most conveniently arranged propagating house.
Fig. 2.