WHAT ARE MY OTHER OPTIONS?
Cold frames
These are low glass or Perspextopped boxes, ideally with a lid that slopes to the south or west. They are great for hardening off seedlings and young plants – getting them accustomed to lower temperatures rather than moving them straight from the greenhouse into the garden.
Although they are not heated, they can be used to raise seedlings a few weeks in advance of those sown outdoors. With the lids raised in summer they can be used for growing courgettes either in growing bags or else planted out in the enriched soil they contain.
Cold frames placed alongside a greenhouse will allow you to move plants swiftly from one environment to another. After a few weeks, with more ventilation given each day, it will be less of a shock to their system when plants are planted out in the garden. Polytunnels
For a relatively inexpensive but large expanse of protected cultivation, polytunnels are your best bet. They are not especially attractive to look at, neither are they hugely retentive of heat (except on sunny days when a door at either end needs to be open to allow a through-flow of air), but they offer protection from wind and rain, and the plants inside them will grow faster than those outdoors. Make sure that the edges of the tunnel are well anchored into the soil. If strong winds get under them, you may find that they have migrated into your neighbour’s garden or even further afield!
Cloches
These are portable minigreenhouses that can be used in spring to bring on early crops of lettuces and the like in advance of those that are grown in open ground. They can also be used to extend late summer sowings of salads into autumn and early winter. Bell jars are hard to find, but Claverton cloches are a modern version of Victorian cloches – tiny greenhouses with removable lids – that are as beautiful as they are useful.