Greenhouse Fever


ConservatoryMy cousin shamed me last summer, when he asserted that it is ridiculous for a vegetable gardener in my climate not to have a greenhouse.

He’s right.  For around $700, I could assemble a plastic-covered hoophouse that might extend arugula season to ten months of the year–maybe the whole year.  Plus, I like the look of hoophouses.  They’re honest.  But they don’t belong in a small, somewhat formal city yard behind a Victorian house.

Unfortunately, it makes more sense for me to have a greenhouse in the city, where I could monitor the whole business, rather than in the country, next to my vegetable garden, where the salad greens would cook on nice spring days.

Amy found the perfect thing for me on eBay, the $21,000 conservatory to the above left.  Sadly, I don’t work in finance. 

Consev2I don’t have the budget, either, for the still-appropriate, but more common $7,500 English conservatory that Smith & Hawken sells.

At the other end of the scale, Lowe’s sells a 6′ by 8′ STC Rion greenhouse for $859 that doesn’t look entirely dissimilar.  It’s green-coated aluminum, with clear polycarbonate.  Last year, one of the wizened old guys who works in the Lowe’s garden center–not in customer service, naturally, those people know nothing–showed me a picture of it and assured me it was really pretty good for the money.

Halls86 Still, I hate the idea of buying anything that isn’t sturdy, particularly given the snowfall here.  A web-site called Envirocept offers some really interesting alternatives.  They carry greenhouse kits by a company named Hall’s and guarantee their aluminum frames for 15 years.  The kits are relatively inexpensive if you supply your own glass, and I care about looks.  I’d just rather have glass.    Their "Universal,"  supposedly one of their heftier models, costs just $629 for the 6 by 8 kit, plus $175 for the steel base.  I priced out the glass for it: $440 for the recommended double thick safety glass.  But the woman behind the counter at the glass place wrinkled her nose as she added it all up.  "It’s just window glass," she said.  "Tempered glass might be better, and that would be roughly double the price."

My older daughter put her arm through a storm door once and sliced it deeply, so I know what that looks like, and I’m not eager to see such a thing again.  Okay, so tempered glass it would have to be.

WoodNow, cost-wise, we’re getting into the realm of the wood greenhouse.

Envirocept sells a 6 by 8 redwood greenhouse kit for $1799.  But somehow, I can’t stand the look of the polycarbonate.    

I can’t help it.  I’m a Luddite.  What I want is glass plus wood.  And that suggests that somebody would have to build it.  Maybe me?  Envirocept also sells a plan for a not-bad-looking wood greenhouse.  But then I’d have to learn some rudimentary carpentry, and I don’t have a good history with such projects, generally abandoning them in favor of the garden as soon as any nice day beckons.

What I really want is some mad money and a patient carpenter.


  1. Okay, I am biased towards the hoop house, but I do have an alternative glass for you.

    Tempered glass is treated glass that fractures into small pieces: think “windshield” and you’ll get what I mean. The glass has been treated, BUT it also has a film on it that holds the glass together.

    I’ll argue it is the plastic film you actually want on your glass if you are worried about the glass breaking. You can therefore get regular old window glass, but you’d need the final step of putting film on its inside face. 3M makes such a product, and so do a lot of other places (google “window film”): think “darkened car windows” and you will see how common it actually is. And yes, it comes in clear. And yes, it is easy to install and remove.

    I have used these products in buildings I have done mainly for privacy reasons (“frosted” glass films are pretty common), but I really don’t see why you can’t use them for your greenhouse. The only downside that I can foresee is it might bubble with the humidity in there, and, like all plastics over time, it will yellow.

    Hope that helps!

  2. Seriously, you don’t want glass in a greenhouse. The main reason is that it weighs too much. A 6ft tall plate typically weighs enough to require two people to lift it. Aluminum is not going to support that kind of weight. It would kill you if it fell on you. Plus the double-layer polycarbonate plastic is better insulation than glass. It won’t be dripping condensation all over you every time you are in there, and it will be better for the plants. I know it doesn’t look exactly the same. I know it’s plastic. But believe me, in the case of a greenhouse that does not require a architect and a building permit, plastic is better than glass.

  3. My dad built one back in the 1970s out of leftover lumber and heavy plastic sheeting…a few nails and a staple gun. One year the propane heater blew up and destroyed it…the greenhouse itself was very sturdy before that happened, though.

    In more recent years before he died he had made little greenhouses with plastic trays and old window frames, some with glass, some with plastic…but this was mainly for getting seedlings ready for the garden, as opposed to having lettuces year-round…still, I would bet the DIY approach would work for a greenhouse, with some patience and elbow grease.

  4. Another vote for polycarbonate., especially double polycarbonate walls.
    That is what I have on my 8×10 greenhouse and it has weathered some pretty rough storms and fallen oak tree branches , and it still stands tall, warm and happy.

    I bought mine as a kit from Charlies’ Greenhouse but would not recommend to anyone that they do the same unless they can read Chinese or understand a strange form of Chinese translated into British English.
    There were so many little seemingly useless tiny little clips and slip on T,L and pins that it took us about 3 weeks ( days and weekends ) to set the darn thing up .( I could have framed it in redwood in a day in a half.)
    Anyone with basic carpentry skill can slap a nice looking greenhouse together in a matter of two weekends and the cost will be less or comparable to one of those frustrating kits.
    ( I still have a bag full of clips and little weird shaped screws that were never installed and the green house has been hold up just fine for the past 6 years or 7 years.

  5. I’ve heard similar warnings about Charlie’s Greenhouse, Michelle. They have a nice line, decent prices but if you lose your sanity while putting it together, it’s not worth it.

    A few Christmases ago, my wonderful hubby gift wrapped a box of greenhouse catalogs. “Pick the one you want,” he said. (I told you he is wonderful.)

    “Thank you! But do you know how much these cost?!” I never bought one. I couldn’t rationalize the cost. Do you know how many tender perennials I could buy each year and still come out ahead?

    Finally, we hit on a solution. He built me one! And for much less than similar greenhouse kits would have cost. You can see it (scroll about half-way down to Monday, 8/13/07 entry). It’s small but it works well for me, it looks nice in my garden and it does just what I need it to; winter over my tender plants.

    We used treated wood for the base, cedar for the frame and polycarbonate 6mm twinwall for the glazing. It has a Dutch door, a window on the opposite side, and roof vents. Our roof pitch is the minimum necessary but we don’t need to worry about snow load.

    As has been pointed out, glass isn’t as good an insulator as polycarbonate. It would never have worked for my small space; the temperatures would have fluctuated too much. Glass looks nice but I think it would put too much pressure on me to keep the inside looking pristine (I don’t do glass kitchen cupboard doors either). And there is the weight issue. If you’re dead set, one option is to use glass sides and polycarbonate roof.

  6. Couldn’t disagree more with the pro-polycarb commenters. My father has been selling greenhouses fror 18 years now and we’ve found very few polycarb models that are up to scratch. If weight of glass as opposed to polycarb is an issue then I’d suggest the building frame is not good enough for the next bit of wind you’ll get.

    For wood and glass greenhouses in Europe this is the manufacturer I’d recommend – I’ve seen 60 year old models that are basically identical to what’s sold today which is proof of concept for me:

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