Winter gardens
Build your own greenhouse for year-long gardening
DAVID MINK GateHouse Plus

While your garden is certainly a seasonal luxury, there are ways to extend your green-thumb hobby throughout the year. Growing indoors is, of course, one example, but with limited space your only real options are a couple of hanging plants and some window-sill herbs.

With a properly constructed greenhouse, however, you can satisfy your gardening needs all year long.

There are many different sizes and styles of greenhouses you can build. If you live in a cold climate, you'll need a highly insulated greenhouse. In warmer climates, you will more than likely need shade control. Regardless, every greenhouse needs ventilation, air circulation, heat in winter, humidity control and pest control.

A greenhouse can be small and inexpensive or large and as luxurious as you can afford. Look into building permits and any restrictions there may be where you live before buying or building a greenhouse, though. Remember, also, greenhouses have to be maintained. You need water, electricity and heat.

The covering you choose to use is important. The best for allowing sunlight and heat is glass, but it is also the most expensive. Plastic sheeting can be used but will deteriorate fairly fast. Fiberglass or other rigid plastics are commonly used with great success, as they have better heat-retaining power than the competitors. In warm climates, a fiberglass greenhouse requires less cooling, as well.

When considering the foundation of your greenhouse, ask yourself how permanent you want this installation to be. If it's temporary, consider simply staking your greenhouse frame to the ground. For a more permanent foundation, use concrete. If you want something in-between, try doing what many others have done and use railroad ties to brace your greenhouse frame.

For those who don't want to build their greenhouse from scratch, many Web sites and home improvement warehouses offer wide selections of greenhouse kits. Depending upon your price range, what style of greenhouse you want and how much space you need, you can usually find the perfect do-it-yourself building kit online.

You will also need to consider running water and electricity to your newly constructed greenhouse. Safety precautions must be taken in the installation and maintenance of both of these, however. For instance, all electrical outlets in your greenhouse should be water resistant and should be used in conjunction with ground fault circuit interrupters. GFCI's monitor the flow of electricity through the outlet and shut the flow off if any variation - such as a sudden surge because of contact with water - is detected.

You will, of course, want to maximize your space in your new greenhouse. Consider installing benches, tables and poles for hanging plants. If you're interested in the amenities, you can install misting systems, automatic watering systems and automatic heating systems. You do need air circulation, so it is nice to have a fan installed.

Cooling and heating the greenhouse is important, but which one you need to be concerned with depends on what part of the country you live in. Northern climates require well-insulated greenhouses.

Southern climates demand cooler greenhouses. Swamp coolers are often used and also shade cloths. Of course ventilation is important in any location.

If your greenhouse is big enough you can store solar heat in different ways. Some use stacked steel barrels filled with water, plastic milk jugs filled with water or a brick or rock wall. There are different solar systems, including active and passive systems. Find out what suits you the best. If you are in an area where the earth can be dug fairly easy, you may want to think about a sunpit. These greenhouses are partly in the ground and this takes advantage of the earths insulation for cooling and heating. Ventilation and the other requirements for greenhouses still apply to sunpits.

- Essortment.com contributed to this article.