| heated greenhouse will extend your growing | | | | small mist propagator for rooting cuttings. A |
| season - a heated one will extend it even further. | | | | cheaper alternative might be a heated propagating |
| A heated greenhouse is normally designed to | | | | case without a mist unit - but this would be less |
| maintain a temperature of 4-7 degrees C (40-45 | | | | effective for cuttings which are difficult to root. |
| degrees F) over winter. | | | | However, a heated propagating case could also |
| It will also ideally contain an automatic ventilation | | | | come in handy for germinating seeds in February |
| system. | | | | or March (later in the year most seeds can be |
| As the temperature inside the hothouse rises | | | | germinated in a pot covered with glass or plastic.) |
| above 21 degrees C (70 degrees F), a ventilator | | | | There might also be staging along the greenhouse |
| in the roof is partially opened by a special | | | | side supporting rows of cuttings which have |
| temperature-sensitive device. If the temperature | | | | already rooted. These can be put into a cold |
| continues to rise, the vent will be fully opened. | | | | frame for hardening later in the year, before |
| Shading can be provided by draw-down blinds on | | | | being transplanted to the garden the following |
| the inside of the glass or plastic, pulled down | | | | spring. |
| manually when there is strong sunshine. If the sun | | | | More staging can hold potted plants in trays of |
| becomes hidden by clouds the blinds can be rolled | | | | wet sand to provide for automatic watering. |
| back up. It's possible to get automatic blinds for | | | | It's quite common to have frames outside the |
| the outside of the greenhouse, but these are | | | | greenhouse. Frames heated by electric cables |
| expensive as they have to be custom-built to fit | | | | make good environments for young plants such |
| your greenhouse's dimensions. | | | | as calceolaria, cineria, and solarum capsicastrum. |
| If the internal temperature falls below 4-7 | | | | Frames without artificial heating might be used to |
| degrees C (40-45 degrees F), an automatic | | | | grow fruits such as melons. |
| heating system can kick in - a thermostat will | | | | A heated greenhouse may be more costly to set |
| switch on an electric fan heater of, say, 2.5 | | | | up and maintain than its unheated cousin, but it |
| kilowatts. | | | | opens up many new gardening possibilities. |
| The greenhouse could contain, in one corner, a | | | | |