Cold Frame Greenhouse - Maximize The Natural Warmth Of The Sun
A cold greenhouse is not warmed by a heating device. The
environment is warmer than the outside - this is due to the
heat of the sun’s rays being trapped inside the covering
material - be it glass or plastic - during the warm season,
and heat accumulated in the soil being released back into
the greenhouse during the fall.
In summer, cool air enters the greenhouse through side
ventilators near the base of the wall, keeping a steady
stream of fresh air flowing around the plants.
The roof might contain larger ventilators to let out air
heated by the sun.
During the hot season it’s quite common to keep all
ventilators and maybe also the doors open at all times, day
and night. In spring and fall, if the day
promises to be sunny, they may be opened in the morning and
closed in the evening.
However, on hot days there is a danger of the plants being
damaged by the fierceness of the sun, and ventilation
doesn’t provide sufficient protection. To counteract this,
the glass can be shaded by an electrostatic shading, which
also offers protection against rain. This shading can be
painted on at the onset of warm weather, and easily wiped
off when the climate turns cooler again.
An electric fan placed on the floor of the greenhouse, or
attached to an end wall, will also aid cooling during very
hot spells, ensuring good circulation of
cool air to keep your plants happy.
Wooden slat staging along the sides of the greenhouse might
support a selection of flowering plants in pots - standing
these in trays of wet sand, fed by a cistern attached to
the wall, should ensure a constant supply of water.
Or, along one side, there might be an open border, the soil
dug over and fortified with leaf-mould or peat. Coarse sand
might be added to heavy clay soil.
This area would be suitable for growing tomatoes, or maybe
a grape vine. A hose fed from a cistern would keep the soil
well watered.
Outside - why not grow late-flowering chrysanthemums in
pots? These can be brought back inside the greenhouse in
September when the tomatoes are ready - and will flower
beautifully in October and November to brighten up the
approach of winter.
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For articles and resources covering all aspects of greenhouse gardening, visit cold frame greenhouse at Greenhousesblog.com |
