If you're an avid gardener, a greenhouse will supply you with the perfect spot to make the most of your hobby. Whether you simply want to prolong the seasons or garden year-round, there is a perfect option for your needs. There are many greenhouse kits and frames to choose from, so you'll need to consider size, material, location and design to make the most of your space.
What are greenhouses used for?
Greenhouses allow plants to be grown all year round by protecting them from disease and external climates, and providing them with a warm and stable environment. They are mostly used for growing vegetables or flowers, but you can grow a variety of different plants in them.
What size greenhouses should I consider?
Greenhouses come in a wide variety of sizes; you can always buy a kit or frame for a predetermined size, or build a unit to accommodate your specific needs. To determine what works for you, consider budget, usage and available space. You'll likely want to go bigger than you'd expect: it's not uncommon to need more room than you'd assume, and upgrading later can be costly. Also think about how you'll use the space: is this going to be a year-round unit or simply a sunroom or sunspace? Certain tasks will require more room than others. Also, don't forget height as head room is important; taller greenhouses are easier to heat and ventilate.
What is the best material for a greenhouse?
In general, you can choose between glass or several types of plastics when it comes to deciding on a material for your greenhouse. Here are some pros and cons of both:
Glass Greenhouses: This is the more traditional covering, and though it's aesthetically appealing, it can have its downfalls. It's inefficient for retaining heat, can crack or break easily, is heavy, and doesn't diffuse light. If you choose glass, it will need to be double or triple strength to increase heating efficiency and protect it from cracks.
Plastic Greenhouses:Plastic options include fibreglass, polycarbonate and polyethylene film, all of which are shatterproof and resistant to hailstone damage. Fibreglass retains heat more efficiently than glass and transmits less heat into the greenhouse. However it can get dirty easily due to its corrugated form and the residue from its gel coat. Polycarbonate retains the clarity of glass and is durable and resistant, but requires several layers for the best quality. Polyethylene film is easy to maintain and is good for heat retention and seasonal needs, but has a relatively short lifespan as it rips and tears more easily than other choices.
What type of ventilation, heating and insulation needs should I consider?
This depends on how you plan to use your glass house. If you want to begin your spring growing early, extend growing into the fall or overwinter plants, you'll want to equip your greenhouse with automatic ventilation and heating. If you're planning to overwinter in a fairly cold climate or grow plants during the winter, you'll need an insulated covering. If you plan to grow plants year round, be sure to tightly seal and insulate it with light transmission, and include an active ventilation system and evaporative cooling system to control heat during the summer.
What type of frame should I use for my greenhouse?
Determine how you will be using yours and where it will be placed to make the right choice on a frame. See below for the typical options:
Galvanised Steel: Low in cost and high in strength, steel frames are durable, long-lasting and require less framework which decreases shadows. However, its polyethylene film will eventually wear off and likely rust.
Aluminium: Easy to maintain yet slightly more expensive, aluminium is the longest lasting due to its inability to rust, rot or break down from UV rays. However, it's not as strong as steel.
Wood:Wood frames are attractive and lose little heat, although may deteriorate easily in a damp unit. If you go the wood route, consider redwood or cedar since they're more resistant to elements and insects and be sure to apply a sealant or stain to prolong its use.
Plastic:Inexpensive and easy to install, plastic frames lose little heat yet tend to be weaker than other options and can deteriorate from too much exposure to ultraviolet rays.
Where should I place my greenhouse?
Place your greenhouse in partial shade if you're using it for starting seeds and transplants, or plant propagation in the summer to minimise heat buildup. If you'll be growing late into the fall or winter, you'll want to maximise sun exposure with the ends of the unit facing east and west. Keep in mind accessibility to electricity and water, and try to place it on a level, well-drained site for easier maintenance.
Do greenhouses require planning permission?
Greenhouses are considered to be outbuildings and therefore are exempt from planning permission and building regulations subject to certain limits and conditions.