There are loads of different types of greenhouses available on the market, but which one is right for you? We take a look at what’s available and how you should choose a greenhouse. A greenhouse is an excellent product to have as it allows gardeners to grow plants and crops all year round regardless of the weather or region.
Recently, new greenhouses have become available on the market thanks to modern materials and new construction techniques. These days, you may see small greenhouses in small residential gardens. Using a greenhouse enables gardeners to extend the growing season, sow plants early and provide the ideal place for rooting cuttings. First, we take a look at what you need to take into consideration before buying a greenhouse.
When it comes to choosing a greenhouse you can choose either aluminium or wood. The majority of people choose aluminium, it does not need any upkeep, and the glazing bars are thin, causing little shade. Wood can be a good choice as well; it may be suited to some garden styles. It will require more upkeep unless you get a bulkier than aluminium and can cast excessive shade inside the greenhouse.
Size & Shape
The taller the greenhouse, the wider the ranger of plants can be grown; this is due to the better light transmission. The eaves should be at least 1.5m (5ft) tall, but ideally they can go up to 1.8m (6ft) or more. You want a door that gives easy access to the greenhouse, so the ridge should be at least 60cm (2ft) above the eaves. There should be a sufficient slope on the greenhouse to shed rain and to encourage loss of excess heat. Domes or other odd-shaped greenhouses can be difficult to manage and can also be more expensive.
You must ensure that your greenhouse has appropriate ventilation; the most useful is roof vents which should be installed on both sides of the ridge and equivalent to 15-20% of the floor area. While louvered vents allow regulation of air, they are hard to draught-proof in the winter. You can use automatic openers that open and close in response to the temperature inside the greenhouse, however they can be slow to respond and manual control may be needed, such as opening some windows and the door each morning.
Glass or Plastic Glazing
Glass is the best glazing material as this lets 90% of the light through; it does not degrade in sunlight and reflects heat radiated from within the glasshouse back into the structure instead of being lost. Polycarbonate sheeting is a twin-walled plastic glazing that has the advantages of being resistant to breakage, lightweight and durable in adverse weather. It is also good at retaining heat. Clear polycarbonate only transmits 83% of the light which may limit its use for growing seedlings, cuttings and plants that require high levels of light.
There are a few types of greenhouses available and we will take a look at what is available.
Cold frames are mini-greenhouses which sit directly on the garden bed for direct seed germination and for hardening off transplants. These types of greenhouses are generally used in early spring to encourage seedlings to sprout and take root. As cold frames are portable you are able to move them around to different beds to follow a spring planting schedule.
These are good if you are just starting out using a greenhouse. They range from small to mid-size and are very popular for propagating seeds and starter plants, which will be transplanted outdoors to garden beds. These greenhouses can also double as a potting shed, where garden supplies can be kept under cover, transplants can be re-potted and harvested crops can be brought in to cure and be processed for winter storage.
These types of greenhouses are generally larger and often feature adjustable shelving. You can grow crops full-term indoors under shelter. These greenhouses are usually all-purpose and are good for propagating seeds, great for indoor growing of crops, and spacious enough for curing harvested crops and preparing them for storage.
Hopefully, this guide will make it easier for you to choose a greenhouse, depending on what you want to use one for and what specifications you want.