The Cold Garden Greenhouse This is where no artificial heat is
used, all heat being directly from the sun. Unless your area is very
mild, this type of greenhouse will be of little use in the winter months.
But in spring it can be used to propagate and/or grow from seeds a wide
variety of plants. The greenhouse will protect the seedlings from the
wind and provide a slightly higher and more even temperature.
In the late spring to summer months a variety of heat loving
vegetables and plants can be grown in the ground inside the greenhouse.
Many plants simply would not thrive in the cold with no protection.
Using a greenhouse in this way will be no problem with all types of
greenhouse. Because it will only be used from Spring onwards, light
levels should be high enough for almost all plants.
The Frost Protect Greenhouse The aim here is to keep a minimum
temperature of 7C (45F) during the winter and spring.
Because plants can be started off early in the year with a greenhouse
of this temperature, good light transmission is necessary. The cost of
heating should also be considered, some greenhouses are better at
retaining heat than others. The use of an electric propagator should also
be considered - how much room will it take up and will there be an
electric supply to the greenhouse?
The Warm Greenhouse The aim here is to keep a minimum
temperature of 13C (55F). At these temperatures it will be possible to
grow plants throughout the year. If this is your plan, light levels will
be very important. You may possibly want to use artificial light at some
time of the year. Is the greenhouse large enough for this and where will
the lights be placed?
The cost of heating a greenhouse to these levels may mean that a
greenhouse with a solid base wall is a good way to reduce costs. Double
or triple glazed polycarbonate may also be a good idea to retain heat.