HOT-BEDS.
The most simple form of Horticultural structures, and one known in almost every garden, is the Hot-bed. To persons of experience in their construction and management, we cannot hope to give any important information, but having seen in many instances the operations of these beds imperfectly performed, we offer a few simple suggestions and directions which will be of advantage to the novice.
The location of the bed should be, if possible, a sheltered one, especially on the north side, while towards the east and south it should be open. This shelter or protection is needed chiefly to prevent an undue radiation of heat from the glass, and the entrance of a strong, cold current of air when the sashes are lifted for ventilation. This radiation is not only hurtful to the plants by causing sudden and extreme changes of temperature, but, if allowed to proceed too far, will cause the heat of the bed to "run out." Let the shelter, therefore, be as thorough as possible.
We have found the south side of a barn, or a tight board fence a good location. The barn would be preferable, on account of its proximity to the materials that furnish the source of heat—the manure pile.
If the soil is wet, or of a heavy nature, it would be better that the bed be made entirely upon the surface. If the situation is a dry one, and the soil gravelly or sandy, then a pit may be excavated, of the size of the intended frame, and three feet in depth. A hollow brick wall should be built up from the bottom, six inches above the surface, if it is intended that the bed should be permanent; otherwise the excavation may be lined with boards, or if designed for only a season's use, it may be left without any support. Hot-beds made under ground require less material, are more lasting in their heat, and require less attention than those built on the surface. On the contrary, should the heat fail from any cause, beds built up on the surface possess the advantage of being more easily renewed by the application of fresh fermenting materials, or "linings" as they are usually termed.
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.