A portable greenhouse sounds as though it should be an impossibility. We tend to think of greenhouses as being made exclusively from metal and glass, but thanks to huge advances in tough and lightweight plastics, nowadays a greenhouse can be manufactured to be incredibly light.
Of course, for most purposes a greenhouse needs to have considerable substance to it to prevent it from being blown away or damaged in high winds. But for a sheltered allotment or garden, a portable version can be an important piece of equipment in your gardening arsenal, allowing you to grow plants in less favourable conditions than usual.
All gardeners know the misery that a late frost can cause, damaging young tender plants and ruining a crop of flowers or vegetables. Cold frames are one solution, but they aren’t cheap to build or to maintain, and you need to have enough space on your plot to accommodate them.
A small portable greenhouse costs much less than a cold frame, with the added benefit that you can use it throughout the year, moving it to wherever it is most needed. You could erect it over tender young shoots in early spring, moving it to a sunnier spot in summer to take full advantage of the sun’s rays. In the winter months it provides much-needed shelter both for you and your winter crops, giving you a head start with seedlings intended for summer growth.
When choosing a portable greenhouse, try to aim for the upper end of your price range. You can pick up some very cheap options, but be warned that they are unlikely to last for more than a season, no matter how carefully you look after them. As with so many things in life, you get what you pay for, so spend time on assessing your requirements before going ahead with your purchase.
Any plastic used in the construction of your portable greenhouse needs to completely UV-resistant: otherwise it will quickly rot or become opaque in sunlight. Staking the walls to the ground should always be your preferred method of anchoring it, as using heavy bricks or stones can easily damage the plastic skin, making your greenhouse useless against cold weather.
Make sure that you have sufficient room to stand up inside your portable greenhouse, as cramp can quickly set in if you are forced to crouch for long periods. Consider whether you should also purchase internal shelving to make the most of the available space. At the higher end of the price range you will find additional accessories that will add value to your portable greenhouse, such as propagators and heaters, but there’s no point in spending extra money until you’ve seen how robust your purchase is.
For DIY aficionados, it’s possible to build your own portable greenhouse, which allows you to customise it to your own exact requirements.