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FrontRangeLiving.com -> Garden -> Green Cathedral
The Green Cathedral--greenhouses are an antidote to winter blues
By Niki Hayden
 Any gardening aficionado will describe a greenhouse as a horticultural
cathedral. A bay laurel stands in the pulpit. Moth orchids form the choir. Right
near the door you’ll find several pews of cherry tomatoes.
Perhaps it’s light filtering through the canopy, or the promise of
unearthly produce in the dead of winter. It could be the hum of fans that form a
chant. A greenhouse creates a calm, ordinary Eden that gardeners cherish. And,
like any Eden, there are a few pests.
"We try to head them off before they start," says Jeff Sorenson,
botanist and co-owner of Rabbit Shadow Farms with greenhouses in Loveland.
Plants are inspected closely for pests and isolated before they’re brought in.
These are the labors that bring any gardener down to earth.
Building a greenhouse, controlling the temperature and managing pests may
sound daunting, but greenhouses are more popular than ever. Once the domain of
kings, or wealthy American colonists, "Thomas Jefferson and George
Washington had greenhouses," says Shane Smith, director of the Botanic
Gardens in Cheyenne, Wyoming, "In the 1950s and accelerating, the average
person found it affordable. My advice is to just set it up as close to a back or
front door as possible. That way, it’s more enjoyable and it will get more
attention," he says.
(See our complete interview with Smith on the new edition of his book,
"Greenhouse Gardener's Companion").
Greenhouses in Colorado date to a carnation boom for the cut flower market in
the 1950s. These days, you’ll find rose and orchid greenhouses. And Colorado is
one of the top states in the country for growing greenhouse tomatoes. "It’s
the growing conditions and the population," Smith says.
 Greenhouses Allow for Winter Gardening
If you’d like a greenhouse, here are a few of the benefits and caveats to
building one in Colorado.
A greenhouse allows more variety for winter gardening. Sorenson strides
between the rows of lavender and coleus topiaries in his three large
greenhouses. Baskets of Mandevilla splendens are laden with scarlet
blooms. An African mallow shrub nestles next to a scented geranium—both
trained in topiary style to sit on a straight stalk with rounded topknot.
Purple sweet allyssum circles the roots of a three-foot topiary of English
lavender. The corkscrew stem winds around a stake. These topiaries are healthy
and bushy, each specimen expertly groomed. They’re perfect for greenhouse
growing because these plants, with the exception of coleus, adjust poorly to
indoor growing. In a greenhouse, they will flourish.
Next, Sorenson bends over his poinsettias. They’re growing a bit hardier
than expected. Sorenson has to keep the greenhouse within cool temperatures for
the herbs. These poinsettias are thriving despite a need for warmth. Still, he
worries about them. Sorenson waves to a newcomer who peers through the young
plants. "I’ll be right there," he says.
Perhaps the newcomer is a vendor. "Not at all," Sorenson whispers.
"He’s from Colorado State University—a specialist in poinsettias. Do
you know how lucky I am that he’s here to look and see if I’m doing anything
wrong?"
 Decide If You Want a Cool or Warm Greenhouse
Sorenson’s dilemma is one that many greenhouse gardeners can identify.
Choosing what to grow in a greenhouse depends on temperatures. "The real
trick," Smith says, "is fitting the right plants into your
greenhouses. If you have to keep it above 65 degrees every night, you’ll
possibly be spending more money than tomatoes are worth. But then, I’m also a
major proponent of people following their passion. Maybe if your passion is
orchids, find the cooler-loving orchids."
At first glance, Colorado appears to offer perfect growing conditions, like
abundant sunshine. The day heats up quickly, so there’s less reason to pay for
fuel. But the temperatures also fall quickly and nights can be brutally cold.
Factor In All the Costs
Greenhouses aren’t cheap. A good kit model costs between $2,000 and $3,000.
Then include the cost of masonry, heating, cooling systems and, finally,
plants. With our altitude, the ultraviolet rays punish any glazing, prematurely
aging it. So, be particular about getting a warranty, Smith advises. While
smaller, cheaper units are coming on the market soon for about $300, it remains
to be seen how popular these simpler models might be.
Factor in the cost of heating in winter. Ironically, solar heated greenhouses—so
appropriate for Colorado conditions—can’t be found in a kit although they
are widely available for commercial greenhouses. You can make one yourself,
Smith says, if you’re at all handy with tools and understand the basic
concept. The Cheyenne Botanic Gardens are totally solar, even when it’s minus
30 degrees outside.
 Consider What You’ll Use for Pest Control
After costs, consider what kind of pest control you’d choose. "Every
greenhouse grower will see that they have to make a decision at some time
whether they want to get to the more environmentally friendly insecticide or the
beneficial critters," Smith says. You’ll find insecticide soaps, fungus
insecticides or cinnamon-laced potions.
Even these environmentally safe materials are not good for the beneficial
insects. For the good bugs to survive you’ll have to encourage some bad bugs.
If you choose to use beneficial insects, accept the lively ecology of one bug
chasing and devouring another. "It’s like learning a whole other type of
gardening. You’re also propagating bugs, It’s just as exciting," Smith
says.
A Colorado benefit is that our dry air keeps mildew and diseases at a low.
But Colorado gardeners, Smith says wryly, are likely to undo that positive
characteristic by over watering.
Sorenson considers climate one of the most important strategies of greenhouse
growing. Originally from Illinois, he remembers hovering over wet soil that
fostered pests and diseases. He prefers the Colorado climate for greenhouse
gardening. Now he keeps the soil a little on the dry side. That’s how he
prevents soil diseases. Fans kick in when necessary to keep an even airflow so
that air is always moving, never stagnant.
 An Emotional Uplifting
Once greenhouse gardeners have made their decision to take the plunge, the
one intangible benefit is the magic of light-filled gardening during dark,
dreary days. It’s not an economic factor in the decision, but many greenhouse
gardeners say that working in a greenhouse in the bleak months of winter is
emotionally uplifting. Being surrounded by green plants, whether flowering or
fruiting, wards off the winter blues. And those benefits are more dramatic in
areas with long dark nights and low temperatures. "It’s the best antidote
to cabin fever." Smith says, "Just take a cup of coffee in and close
the door."
Rabbit Shadow Farms are owned by brother and sister, Kristy and Jeff
Sorenson. They specialize in topiary, herbs, bedding plants, container gardens
and perennials. Located at 2880 E. Hwy 402 in Loveland, they can be reached at
1-800-850-5531.
Shane Smith’s book, "Greenhouse Gardening" is published by
Fulcrum Books in Golden, Colorado. They’re on the web at www.fulcrum-books.com.
Smith’s website is at:
www.greenhousegarden.com.
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