Hot-Bed And Cold-Frame
( Originally Published 1909 )
ONE of the first things to be done in spring in the line of gardening operations is the making of a hot-bed in which to grow plants for transplanting to the garden as soon as the weather will permit. While I would not advise anyone to depend on seedlings grown in the hot-bed for a general crop of any vegetable, I would advise starting a quantity of each kind from which an early crop is desired. Those who would like to grow vegetables for market will find it very important to get them under way early in the season, if they would reap the benefit of good prices. A well-constructed hot-bed, well cared for, will enable the gardener to have vegetables of certain kinds nearly a month earlier than he can hope to have if he depends on the garden for them.
The location of the hot-bed is a matter of considerable importance. It should be on a soil that has good drainage, in a place well sheltered from wind, and fully exposed to the sun. It should also be near the house, for convenience in giving it frequent attention.
Let me say, right here, that the idea that almost anything in the shape of a pile of manure with a few boards about it and a covering of sash will answer all the purposes of a hot-bed, as well as a more carefully constructed arrangement would, is wrong. To do good work—and you want that or nothing—you must construct your hot-bed as thoroughly as you would your poultry-house, or your stable. A make-shift affair is not one in which you will be likely to grow good plants, but will be a constant source of annoyance to you, and will very likely be the cause of entire failure in the growing of seedlings for early planting out. Therefore build with a view to substantial results.
Fresh manure from the horse stable, mixed with litter from bedding, is the material most generally made use of to furnish the heat required in the hot-bed. A quantity of this material is spread on the site selected for the hot-bed, covering a space somewhat larger than the bed itself is expected to be. Spread it in layers a few inches in depth, and tramp down each layer before another is added.
When the pile is eighteen inches or two feet in depth, finish off by rounding it over in such a manner that it will shed rain, or cover it with oil-cloth. Leave it in this condition for a few days till fermentation sets in. This can be told by a warm moisture which will be seen rising from it. The mass should then be well forked over, shaking out the long straw, as this is done, and made into another compact heap, as at first. In two or three days it will give evidence of further heating. After this it is likely to be in a condition for final disposition in the bed. As the manure is now thrown into shape, pack it down well, making it as uniformly compact as possible. It is quite important that the foundation should have considerable solidity, as you will soon discover that a heap of loose litter amounts to next to nothing for hot-bed purposes. There should be not less than two feet of this material.
The frame, which the wise gardener will have constructed in advance of the season, should now be put in place, and fitted with sash. Bank up well outside the frame with coarse manure, firmly packed down. Allow the sash to remain in place until strong heat is generated. When this begins to decrease and the thermometer does not register more than 85° or 900, cover the manure inside the frame with about six inches of the finest and mellowest soil you can obtain. When this is done, the bed is ready for use.
The making of a hot-bed frame is a simple piece of carpentering. At the back it should be about eighteen inches high. If it is six feet wide there should be a slope of six or eight inches towards the sun. This would make the front ten or twelve inches deep, according to the slope decided on. The slope is one of the important things to consider, for the sash should be of just the right angle to receive the fullest possible benefit from the sun. If too flat, or too abrupt, you fail to get the warmth desired. Therefore satisfy yourself as to the angle that would be most satisfactory, and make other matters subordinate to it.
Bevel the back and front of the boards of the frame, that the sash may hug closely and fit snugly all around. Care should be taken, in putting the frame together, to have every joint perfect, for poor joints and ill-fitting sash will allow heat to escape more rapidly than it is generated, thus making the hot-bed a failure.
If more than one sash is used to each frame or section, a stout piece of wood should run from front to back for the pieces of sash to rest on, where they meet. If large pieces of sash are used, they will be found quite heavy, and the frame and its cross-strips should be substantially made, or there may be a collapse at a time when such a happening would be disastrous in the extreme. It pays to do good work, while you are about it. A good hot-bed frame will do duty for several seasons, if well constructed and properly cared for after it is emptied of its seedlings.
It often happens that we have severe weather after we get the hot-bed in operation. In such cases we must cover the sash with something that will prevent frost from forming on the glass and radiating cold down upon the delicate young plants. Strips of matting, old carpet, or blankets, will answer as well as anything.
If the weather is bright and warm, it will be necessary to admit a little air to hot-bed seedlings during the middle of the day; but do not lift the sash very much, and be sure that no cold wind can blow in upon the tender plants. To facilitate this part of the work, it is a good plan to have the sash hung with hinges, at the back of the frame. If this is done, they can be raised or lowered without slipping out of place, as they will be quite likely to do if simply placed over the frame without fastening.
In sowing seed in the hot-bed, cover lightly with soil and press the latter down enough to make it somewhat firm, but do not pack it solidly. Water can be applied, as needed, with a watering-pot having a spray nozzle. Never use a stream when watering plants in the hot-bed, as that will wash the soil away from the roots of the plants. If the glass be-comes covered with moisture, after watering or from evaporation at any time during the day, lift the sash a little to allow the surplus moisture to pass off, and clear the glass so that the rays of the sun will be enabled to get to the plants freely.
A cold-frame is almost as important as a hot-bed. The two ought always to go together. It is simply a frame of boards constructed like that of the hot-bed, and set over a quantity of rich soil into which the seedlings from the hot-bed are transplanted when they have attained some size. This frame should also be fitted with a covering of sash. This should be lifted on all pleasant days, to give the plants inside the benefit of fresh air, and thus harden them for the time when they must go into the ground outside. At night and on all cold days the sash must be closed to retain the necessary degree of warmth. A little chilly weather will often injure the plants quite as much as a touch of frost would.
In sunny weather be sure to open the cold-frame before the heat of the sun, by concentration on the glass becomes too intense for the young plants. The admission of fresh air will counteract all danger from this source.
The temperature in the cold-frame ought to range between 6o° and 65° if one would grow strong and healthy plants, and of course one wants to grow nothing else.
It will readily be understood from what has been said that both hot-bed and cold-frame will require considerable attention. They can-not be expected to take care of themselves after being built. They must be regulated according to the weather. Air must be admitted whenever it is possible to do so without injury to the plants, and cold draughts must be avoided as one would avoid the plague. It will be necessary to consult the thermometer a good many times a day. That is what must be depended on more than anything else in the management of hot-bed and cold-frame.
In the north the first of March is quite early enough to start a hot-bed for the growing of very early vegetables, and a month later for plants intended for general garden use.
It is not advisable to have plants remain in either hot-bed or cold-frame so long that they become weakened by too long-continued heat. Injury of this kind can only be prevented by the proper admission of fresh air, and the regulation of the temperature as already advised. I make mention of this again because it is some-thing that no gardener can afford to ignore, and I desire to fully impress the fact upon his mind.
Do not take the trouble to start any of the ordinary vegetables, which mature during the latter part of summer in the garden, in the hot-bed. They will come ahead rapidly enough if planted in the open ground, where they will be much easier to care for.