What to look for in a kit greenhouse

QI want a small greenhouse. Our budget is tight, so we need an inexpensive kit and a greenhousse that does not need a lot of heat. What low-cost kits would you recommend? ?

AThere are do-it-yourself greenhouse kits designed to meet nearly every budget and style preference. Some kits cost only several hundred dollars. They are not fancy, but they do the job. There are also smaller collapsible models that you can quickly store away.

If you plan to attempt to grow vegetables and flowers year-round in a very cold climate, you will need to heat the greenhouse. To minimize the heating costs, select one with double glazing or a lean-to model that you can attach to your house. During milder weather, the lean-to greenhouse can help heat your house free.

There are many unique and decorative greenhouse styles available that can make an attractive and functional addition to your landscaping. New circular, gazebo-style greenhouses are ideal for starting flowers in flats and for hanging plants. Other designs have a tall arch-style roof.

Greenhouse kits are specifically designed for growing plants as compared to sunroom kits for living space. Most kit suppliers also offer special slat and soil benches (for plant propagation in flats). To maintain an even, year-round temperature, screens, automatic vents, heaters and fans are available

When selecting a do-it-yourself greenhouse kit, the most important factors for cost-considerations are the framing design and glazing material. Aluminum probably is the most common, reasonably-priced framing material. Redwood and cedar are more attractive, but require some maintenance.

For your low budget, consider a kit that uses a PVC pipe frame. The precut, color-coded pieces are delivered to your home. The connectors are metal reinforced and you glue the pieces together like plastic drain pipe. If you choose aluminum, steel or wood frames, they are predrilled at the factory.

The primary glazing options are glass, rigid plastic and 6-mil plastic film. Single-pane glass or clear acrylic plastic are good, reasonably-priced options. Rigid flat fiberglass is somewhat more expensive, but it is very strong. Although it looks cloudy, it lets all the necessary light through.

Clear film is very inexpensive and simple to install. The PVC frame design uses clear film. The film is tough and filters out harsh UV rays.

My house does not have a whole-house humidifier on the central furnace/air conditioning duct system. How can I tell if I need a humidifier?

First, it is easier to determine if you have too much humidity. The primary sign of this in cold climates is sweating windows. In warmer climates, mold growth and a musty smell indicate too much moisture.

If you do not have these symptoms, look for signs of excessive dryness. These include loose joints in furniture and doors, cracks at wall corners, static electricity and your cat's hair standing on end when you pet her.

-- Send questions to James Dulley, Star Tribune column, 6906 Royalgreen Dr., Cincinnati, OH 45244. For more information on greenhouse kits, write him for Update Bulletin No. 911. Include $3 and a self-addressed, business-size envelope. To contact him or read previous columns, his Web page is http://www.dulley.com