Making a Mini Greenhouse

15 years ago

I live in Austin Texas and this is my second planting year I have had a lot of successes and several failures with vegetable gardening. I have found out that heat is a problem with many vegetables. This year I am trying tomatoes, which I planted from seed, since I've heard other people have had good experiences with tomatoes.

Unbeknownst to me but knownst to other more experienced gardeners even tomatoes can be susceptible to heat. Thankfully I tried two species and one seems to be much more heat tolerant.

Anyway, I am tired of heat problems and I am ready to try a mini greenhouse and I mean mini, maybe 6 to 8 square feet and 2 to 3 feet tall. Because heat seems to be my problem for the kind of plants I want, I found that good covering and evaporative cooling can really work.

I have calculated that for 50 cubic feet even a computer fans would work, Although I may need something sturdier, and for a cooling pad I only need around half square foot.

I know that most people have Polyethilene film on their greenhouses, But I'm not sure if that is all they have. I'm thinking I could tape the film into a box shape supported by a frame and tape zippers to access the inside. But I need to know how flexible the film is, does it fold like paper or like cloth? Would I need something besides the film for the sun or maybe hail?

The last question I would have is if it would be a good idea to buy a device that would record temperature and humidity as I put this together to make sure I'm actually getting what I want.

If all goes well I'll be able to use this experience in a future bigger greenhouse. Any help will be greatly appreciated.

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Comments (6)

arturoh
Original Author
15 years ago
I am embarking myself in the project of making a small 6 square feet 3 to 4 feet tall greenhouse. I think I have most things figured out. I think. I am starting small so problems don't turn into nightmares.

But I have not been able to find a place where I can buy a small cooling pad. For the size of greenhouse I think I only need a third of a square foot. It may be more practical to go a bit bigger. And extra backup pad would be a good thing. So I'm probably looking for 2 or 3 square feet of cooling pad.

And I just can't find anyone that would sell so little.

I am to the point that I am considering taking a bunch of cardboard boxes I have in the garage cutting them into slits and gluing them together. Although from the looks of what I see on the internet the groves (holes) look much bigger than the ones on the cardboard. So I suppose it could create a difference in pressure. And maybe It should be thinner...... Ughh

If anybody knows where to buy a small cooling pad or has an extra one that they would sell, any information will b greatly appreciated. FYI I live in Austin, TX
cactusfreak
15 years ago
A smaller greenhouse will be harder to cool.
I don't think your idea is practical.
The intensity of the sun rays will still burn your plants being that close to plastic or glass, even if you were able to keep the temperature down a few degrees.
Even in an air conditioned room if you have house plants setting in front of a window they will burn.
You would have to shade them so much they will not get the needed sun rays.
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shebear
15 years ago
Why don't you just cover the greenhouse with shade cloth. It can drop the temps up to 10 degrees. Just like a tree only it is mobile and comes in different shade percents.
anettemartinrn
15 years ago
a lath house might be more practical for your needs. good luck.

anette
oakhill (zone 9A, Calif.)
15 years ago
Cooling pads, either aspen or synthetic, cost a maximum of $8 for 2 square ft. at most hardware stores. The larger expense will be the pump, hoses, connections and water reservoir for your evaporative pad system. What are your plans for this part of your system?
arturoh
Original Author
15 years ago
Cuestaroble,

As far as pump hoses and everything else. I think I could build a frame with some extra aluminum I have in the garage from a previous project. And I already have a mini pump that should fit the water requirement since I read that it is somewhere in the neighborhood of 2 gallon per foot per minute. And this little pump I have, I believe is rated for 200 GPH

As far as the sump. I have the benefit of having a very small installation so I could just let the water drain though a hose to a small black container and place the pump inside. I know maintenance can be a big problem. I think the worst case scenario for me would be replacing the water once a week. The one thing I do not know is how fast water would evaporate, again I hope scale would work in my favor.

I think I have everything I need but perhaps come connectors and of course the cooling pad. I went to my local hardware stores here in Austin, Texas. And they did not have cooling pads. They suggested I check with an HVAC supplier.

Making a Mini Greenhouse

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arturoh
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Making a Mini Greenhouse

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