Undercover: Getting the most from your garden's greenhouse

There comes a point in a novice gardener's life when they will ask themselves the question "Do I need a greenhouse?" Greenhouses offer certainty in terms of growing conditions - vital with topsy turvy British climate changes.

After all who wants to see their prized crops and topsoil washed away by flash flooding? Similarly, if you are serious about propagating your own plants, then a snug greenhouse means you can start plants early, so that they are well developed when the weather becomes warm enough to transfer them outdoors.

A traditional glass fitted, timber or aluminium greenhouse is a major investment, costing over £1,000 on average. It will require a solid, level site for it to sit on - some designs require brick or cement foundations to be in place.

However, for homeowners with small gardens, there are much simpler and more affordable alternatives in the form of mini greenhouses, which are essentially frames with a clear polythene cover, incorporating racks.

Another useful greenhouse alternative for gardens with limited room are cold frames. Essentially these are boxes with a sloping glass or plastic lid, which can be made from brick, timber, metal or glass.

Greenhouse designs

Greenhouses vary in shape and style. The classic and most popular design is a rectangular shape with a pitched roof. There are also heptagonal and octagonal designs, which are also ideal for smaller gardens.

Lean-to greenhouses can be built against the wall of your house or garage, or even a garden shed and offer good head room. If properly thought out, they can be extremely attractive and can double up as conservatories.

Glass versus plastic

The best form of glazing is glass, as it transmits light more efficiently than plastic. It also reflects heat better and doesn't degrade. The most common glass is standard horticultural glass, which is clear, practical and affordable. However, it is not ideal if you have exuberant pets or children around, as it can break very easily.

Toughened safety glass is more expensive but a safer choice in a family environment. Another good choice is polycarbonate safety glazing, which is light and shatterproof, with an opaque finish.

Aluminium or timber?

In terms of style, it's hard to beat a classic wooden greenhouse, but if you do opt for one, make sure that the timber has been pressure treated, which will extend the lifetime of the structure and require lower maintenance. On the other hand, aluminium, either in a natural finish or painted, is less bulky than a wooden greenhouse, plus it requires no upkeep and is both light and durable.

Captions:

1. This modern greenhouse is a glass to ground model made from a combination of timber framework with aluminium glazing panels.

2. The dome shaped Garden Igloo is a funky looking multipurpose greenhouse that is made from PVC and can be used all year round. The transparent dome retains and has two windows plus a door.

3.Choose a sunny wall to site a lean-to greenhouse and make sure it is well ventilated as you want to ensure that a constant supply of cool air enters the greenhouse, as it will help growing conditions.

4. An affordable option to a greenhouse is a mini greenhouse, which is ideal for small gardens, patios or even balconies and can be used for raising seedlings or cultivating plants.