There are two basic types of growing frames that will increase your crops yield, Cold Frames and Hot Frames.
These are simple wooden, plastic, or even cardboard boxes, frames, which can be turned into top notch growth aids when used correctly.
Both types of growing frames, cold and hot, will be discussed here. The main purpose of using either type of frame is to maximize your use of the days during a growing season.
Cannabis sativa and indica strains are generally photoperiodic, which means their flowering phases are triggered by a shortening of the days. The lengthening of days which begins after midwinter, and persists through late June, should be fully exploited to prolong the growing season, so that bigger plants and ultimately more flowers are grown.
Some cannabis strains will flower earlier than the 180+ days available, no matter what is done. Efficient utilization of a plants vegetative stage of growth by early starting will assure each plant reaches its maximum size before flowering.
It is possible to secure nearly 6 months of outdoor growing time BEFORE flowering is triggered, once frost is defeated and early germination is achieved.
Cold and hot frames facilitate early germination and allow a grower to bring plants to more hardy vegetative growth, setting up a synergy whereby the plant reaches its growth peak, a vigorous vegetative state, just as its environment starts to become more friendly, as summer comes on.
For outdoor growers, longer growing seasons mean larger plants thus bigger crops. Get them started early. The earlier the better. That is the whole point of using frames to make bigger crops.
Cold frames can be elaborate hand-made wooden boxes with glass that can be swung up and down via pulleys and ropes, or as simple as surplus house windows placed over shallow holes in the ground. This is a time honoured way of creating and preserving an above freezing temperature in even some of the coldest parts of the world.
In New Mexico, various native peoples have used the hole in the ground for winter gardening for a long time.
Called Walpini, among other things, these holes in the ground are dug about 3 feet deep, and the dirt that is removed is used with rocks to make a 2 foot wall around the outer edge, which is then covered with sheeting over poles laid across the top.
Opened to the sun and rain during the day, then covered at night, whole crops can be produced this way in otherwise forbidding conditions.
Every geographical area has its subterranean greenhouse farmers; it pays to seek out the people with the know-how in your own area, and to obtain old books on agriculture too, whenever possible.
Cold frames are called col frames because no source of heat other than the sun and the earth are used to create the environment within. Hot frames are the same basic type of thing, a miniature greenhouse utilizing the sun, but also using some source of heat, like an electric heating pad, or even compost heaters made from porcelain tanks full of decomposing horse manure.
A good layer of horse manure in a cold frame constitutes its change to a hot frame, because the decomposing manure, well tamped and covered with sand, will be a constant source of low grade heat for a long time. Always leave any container of decomposing material UNCOVERED, or well vented at least.
The trouble with Hot Frames is desiccation; they tend to dry out too quickly, and must be monitored constantly. Use spray bottles to mist and keep the local humidity up inside a hot frame, and be attentive, even sensitive to the interior heat at all times. Thermometers are a good idea with hot frames. Many hot frames are left totally open during the daylight hours, and are employed only when freeze danger is imminent.
Within 4 to 5 weeks of germination, the seedlings will enter their vegetative stage of growth if all goes well. Here is where cold weather is your ally. The small plants can be gradually exposed to
colder weather for longer times outside of their frames, and in full sun, during late winter days.
This is called Hardening of the plants, and you will see them react to these conditions with healthy full growth most of the time. As they begin to truly thrive and all threat of frost passes, they can be left out at night as well, thereby finishing them in preparation for their long growing season.
The main thing to be avoided during this early maturation process, or any other greenhouse process, is transplanting, because no matter how hard you try, you really break a lot of roots in
transplanting, and it stresses the plant at just the time when it should not be.
Always take good care to use easily removed paper cups to start your seedlings, and transplant only once, using plenty of water, to the final pot or place in the ground.
Never touch roots! If your plants are to be outdoor plants, planted in the ground itself, it is a good idea to cage them with wire mesh baskets after transplanting into the ground, until they reach a foot or two in height.