Six years ago, Kay Baxter fulfilled a lifelong dream, and installed a greenhouse off her family room. She loves it. She talks about her plants as though they were family. Many of them she’s had for years, since before her 19-year-old son was born. Watching her look around fondly at her plant friends, you can see that they take care of her as much as she does of them.
Baxter’s greenhouse, on the North Shore, is filled with beautiful colors and wonderful smells. She has orchids in full bloom, their wand-like stems bending gently under the lovely burden of their moon-faced flowers, a confederate jasmine covered in tiny star-shaped flowers, a deep pink camelia that’s just finished blooming.
Whether you like plants as a hobby, as therapy, or to eat, there’s something magical about greenhouses. You step into a humid, sun-drenched room filled with lush greens. The cares of the world melt away when the delicate scent of jasmine mixes with the smell of freshly turned soil.
Most gardeners at some point fantasize about having a greenhouse, but a greenhouse doesn’t have to be just a fantasy. Just ask Jim Alyea of Alyea Greenhouses in Wheaton. He installed Baxter’s greenhouse, and he’s been installing greenhouses since 1978, when he first installed one for himself.
To figure out what greenhouse is right for you, Alyea recommends starting with who’s going to use it. A greenhouse or glass house is for plants. It’s generally separate from your house, and has a dirt floor with pea gravel to maintain high humidity.
A solarium or sun room is for people. It’s connected to your house, with a tile or concrete floor, shades and no automatic venting.
Then there are conservatories for both plants and people, the creme de la creme of the greenhouse world, with vaulted ceilings, finials and lots of decorative ironwork.
Next, figure out how big your greenhouse should be. Baxter is adamant. “Make it bigger than you want. I could have made mine twice as big. I’ve had to get rid of so many plants.”
The Hobby Greenhouse Association (www.orbitworld.net/hga) provides a forum for greenhousing enthusiasts. HGA agrees with Baxter that bigger is better. The association adds that “it is more efficient and cost-effective to build the larger structure in the beginning.” It’s also easier to control the temperature in a larger greenhouse.
One of the things HGA provides is a directory of more than 60 suppliers, to help you find the greenhouse that’s just right for you. The group also has lots of advice on situating and designing your greenhouse.
HGA says that ideally “one long side of the greenhouse should face south, southeast or southwest, and one end should catch the morning sun.” Practically, though, you have to locate it in the way that makes the most sense for your house. Baxter’s is attached to a north-facing wall because that’s where her family room faced, and she wanted to be able to walk easily out to visit her plants.
As far as to-attach-or-not goes, the HGA says free-standing greenhouses get the most light, since every surface is exposed to the sky. But you may not want to walk across a snowy expanse to check on the seedlings. Greenhouses that are attached to a wall of your house share your house’s heat, an important consideration in the Midwest. And you can easily step from home to “garden” without donning even a light cardigan.
Lean-to greenhouse
There are “lean-to” and “even-span” greenhouses. Lean-tos run parallel to an outside wall, and the roof slopes downward. According to HGA, they are the easiest of the attached greenhouses to build, and incur the least heat loss. Janice Hale, HGA’s director of publications has a lean-to against her house. “It’s only 6 by 16, but it’s stuffed with plants,” she says.
Even-span greenhouses have pitched roofs, and are either free-standing or attached to your house along one wall. HGA says the latter combines the advantages of a free-standing greenhouse with those of a lean-to: light can enter through three sides and the roof, and people can access it easily.
A crucial question in the design of your greenhouse is whether to use glass or polycarbonate. Thomas Eckert, HGA vice president, included a section on glazing in the latest Hobby Greenhouse, the HGA magazine. Glass, he says, is probably the choice for most hobby greenhousers, but polycarbonate has some advantages.
The best thing about glass is that it’s see-through. The problem is that it’s brittle, vulnerable to falling branches, hail, and misfired baseballs.
Polycarbonate, on the other hand, isn’t see-through. But in its favor is its strength, Eckert says, “I took a hammer and gave it a good whack while it was lying on top of the steel welding table in my shop.” It didn’t break. There was a dent, but not even any cracks.
Now that you know the basics, you might want to find out whether a greenhouse kit is right for you. A kit has the same parts as the greenhouses that Alyea installs, but a homeowner would have to do all the concrete work and assembly. Jim Campbell of Campbell Glasshouses Inc. in Lincolnshire says that though kits are inexpensive, “they are of minimal quality and durability in this climate.”
For a discussion of kit pros and cons and a list of kit suppliers, check out The Greenhouse Gardener’s Companion (www.greenhousegarden.com).
Once you’ve decided on location and design, get started on building your greenhouse. Campbell says building codes dictate the type of foundation required for greenhouses attached to your house. “Full footing and foundation walls are required today in most communities.”
The foundation
Ideally, notes Alyea, a greenhouse has no concrete slab. “You can water plants and let the water soak into the ground and release humidity into the air.” To support the walls, he fills a foundation trench with concrete. Then he assembles the greenhouse.
The whole process takes several weeks, including inspections and concrete.
Last but not least, what could realizing your lifelong dream of having a greenhouse set you back? Alyea Greenhouses can supply you with a kit for $3,000-$5,000. “For a greenhouse that we install, $10,000 covers a turnkey operation on a small 10-by-10 foot house.”
According to Campbell Glasshouses, “A hobby greenhouse can be obtained for several thousand dollars and a beautiful conservatory may cost $50,000 to $75,000.”
OK, so maybe a conservatory is out of the question, but wouldn’t a nice little corner of paradise be perfect off the family room next January?
Greenhouse essentials
Once you’ve decided to go ahead with a greenhouse, have some fun adding the bells and whistles. Here are some suggestions from the Hobby Greenhouse Association:
Adequate ventilation and good air circulation are extremely important to control temperatures, prevent mildew and condensation, and for fresh air and carbon dioxide:
– Venting system to promote natural air convection
– Gable exhaust fans to move air through the greenhouse
– Most greenhouses will need some type of heater:
– Space heaters are an efficient and frequent choice
– Solar greenhouses rely on the sun for all or part of their heat
– Fans and vents may provide adequate cooling for most months, but in the heat of the summer you may need to:
– Paint roof with whitewash or a special shading compound
– Cover roof with shade cloth screening or roller shades
– Install a swamp cooler
– Just move your plants outside for the summer
Other nice toys:
– Maximum minimum thermometer and a humidity gauge to monitor the interior environment
– Temperature alarm
– Automatic watering system
–Emerson Howell Nagel
