Taro & Ti Hothouse

I have for years pushed the limits of whatever growing space I was utilizing. For the longest time that meant windows crowded with plants, rows of plant-lights in various locations of my hale - whatever house or apartment I called home, plant shelves brimming with plants and so forth. As a bachelor, that was all well and fine - but as a married man, all that began to change immediately. Gradually, my collections began to coalesce into less conspicuous locations - the plant shelves disappeared, as did the plant-lights haphazardly placed in any open space. With our current house, I now get an east-facing picture window and a south-facing closet of an office. Needless to say, the picture window is almost always crowded - sometimes a point of irritation for my better half, and my office is even now still full of pots of various plants, vines and… dirt.

Folks, it was time for me to grow up and move out - it was time for a greenhouse.

I have earnestly desired a greenhouse for years, but had never gotten the gumption to actually build one. But as my plants had spilled out of the house, all growing larger and larger both in size and number, gumption or no, if I wanted them to survive the winter, a greenhouse was the only way. I had at the time recently acquired over 30 varieties of taro, had my bananas, chocolate trees, coffee trees, lemongrass, cashews and a host of other tropicals that simply would not fit inside the house.

I did a lot of cost analysis on different greenhouses and kept coming back to the elegant and super simple live-stock panel design. It was a marvel of simplicity. Livestock panels are heavy-gauge welded wire panels that are 52″ wide and 16′ long. They remain springy even if curved, which is the secret to their sturdiness. When curved with the short ends placed 9′ apart, they form a hoop that is approximately 6′ tall - perfect for all but the tallest of us.

First thing I did was determine approximately how long I wanted the greenhouse to be. Me, I always think big so I made mine twice as long as I really needed - which had its drawbacks when it came to heating the thing. Only go as long as you need - you can always add on later very easily by adding more panels.

Nevertheless, I promptly had the panels delivered - eight of them for my 33′ long greenhouse. They were very inexpensive - less that $20 each at the time. I also got a roll of 20×100′ 6mil basic poly. I could have gone with a greenhouse poly, but at the time I didn’t have that extra $150 or so burning a hole in my pocket, so I chose a much cheaper but much shorter-lived general translucent poly from the hardware store. To connect the panels I chose zip-ties. They’re a good one-season solution - but if you plan on making this permanent, get some bailing wire instead. I never got around to framing the ends of this particular greenhouse - I considered it as temporary so I didn’t bother with it.

I marked out where the panels would go. For my temporary greenhouse, I was staking them directly in the ground. Sturdy tent-stakes work well - use a lot of them. Then I took a panel and curved it into place. They are rather stiff - having a helping hand would have helped enormously. But, kids were too young and wife had a real job. Anyway - I step back and admire my first hoop - only to realize that the short wires are on the outside. With them thus, after I put the poly on, their ends would rub holes in the poly. So… I de-hooped it and re-hooped it with the long wires on the outside.

I put the rest of them up, next to each other. Unconnected, they’re a bit wobbly, but they maintain their hoop very well. Out came the zipties. I chose to zip them together where the long and short wires were welded, matching each panel up together. That way there’d be less shifting. It didn’t take long to get them all zipped up. I’d have taken pictures of the construction process but at the time I was in a panic-manic because a cold-front was coming thru and the greenhouse had to be done then and there before I left for work. Nevertheless - the simplicity of construction can’t be overstated.

Once I had them all ziptied together, I decided to put pipe-insulation on each end to keep the poly from rubbing on the wire ends. For a greenhouse this length, there is a fair amount of shifting as the poly warms up in the day and chills down at night - it got tight as a drum on really frigid days - so protecting the poly on points where it’ll rub is important.

As to its effectiveness - the minute I got the poly draped over the hoop - something I did completely solo, working with the wind, inside it got steamy hot almost immediately. That was comforting. In retrospect, though, I should have built ends for the greenhouse - in this case I draped the poly instead and anchored it on the ground. It made my job harder in opening the poly to let air flow thru, then closing it every night - a pair of easily made vents would have been much easier.

Now, connecting the poly to the greenhouse. Since mine was temporary and directly staked to the ground, I didn’t have a wooden footer to attach it to. But I had a stack of pallets and a stack of old hay bales. In a time crunch, I made use of what I had - laying the pallets on the ends of the poly to anchor them tight, and weighing them down with hay bales. It actually worked pretty well. I used hay-bales to anchor the draped ends too. It wasn’t perfect - but it did the job I intended for it to do.

Alternatively - were I to build this thing today, I would use a footer frame. But, this may come as a surprise - I would be less concerned with stapling the plastic to the frame. You see, I had a little problem that Spring - the shrinking and expanding and wind-flapping had caused rips. By the time Spring came around, the poly was more brittle from solar exposure and in time I had duct-tape holding it all together. It made it tho - it didn’t start ripping until it was almost time for me to take it off. But, it was still a bit disconcerting - if it rips at night and a cold front comes thru things could get ugly. My current solution is simple - limit the length of tears by placing another set of cattle-panels on the outside! I hoop those over the poly-covered hoops and simply anchored it to the wooden frame by nails - the tension of the springiness keeps it in place and… no flapping! Tears that form stick to one little square rather than migrating. That will be covered in another article tho - however I feel that solution may help some reading this article…

I put down some pallets on the inside of this hoop-house and started moving plants in. None-too-soon too - the cold-front was already making things brisk. I folded up the plastic at the ends and that was that - off to work. The next day I went out and opened the ends to keep it from over-heating - everything survived a freezing night with no heat at all.

Since I had made the greenhouse so long, my heating plan shifted from total ambient warmth to localized warmth - I set the simple hardware heaters - two of them - to cover the collection of plants and create a little heat-bubble around them, even tho the rest of the greenhouse would get rather chilly. That worked pretty well too. Protect your heaters from greenhouse-rain tho. The humidity will condense on the poly and it will drip light rain. I found it particularly amusing walking in there with dry hair and leaving pretty wet. Your plants may suffer some cold-drip leaf damage (cold water drops dripping on leaves), but it’s really minor. Working out there in the rain can be noisy too - but it was pretty neat. I put a little florescent light out there so I could go out there and pot stuff up after work.

Greenhouses grow on you if you don’t over-stress your wallet and time. Mine was cheap, easy to build, easy to maintain and fun to work in. My current pit-greenhouse re-used some of the materials that comprised this greenhouse - the hoops are still hoops. But I may build a few more topside greenhouses to cover some taro beds to extend their season a bit here. If I were to try to do this with conventional greenhouses, it would be impossible just from a cost perspective.

If you decide to do this method, please let me know how it works for you and send me pictures. This kind of DIY greenhouse always inspires creativity and I’ve seen some pretty neat solutions out there.

Stumble it!

This entry was posted on Tuesday, February 26th, 2008 at 8:38 am and is filed under Articles: Howto . You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.