Greenhouse CatAsTrophe

We've been having a tough time in the greenhouse. These are some leeks from the greenhouse. Yes, those are teethmarks on them. Somebody, probably several somebodies are using our greenhouse as their own winter larder. Probably voles or mice. They have wiped out the greens and other starts. It's been discouraging. We're not sure what to do different for next year. I don't really want to do a foundation. Maybe we had the plastic on too soon, we should have let the ground freeze. It will take some thought for next year.

The rodents aren't all. If we were too far ahead putting on the plastic, we were too late with the bracing cords. On Thursday night we got a small snow storm and then heavy rain. Freezing rain. We were luckier than people north and south of us, there 25,000 power customers without it and we only lost it briefly overnight. But the waterlogged snow was too much weight for the inadequately braced greenhouse.

In the past we have braced the greenhouse with cords that act like spokes, maintaining the curve of the greenhouse. If there are enough of these cords, the strength of the 1/4" steel that makes up the cattle panel will hold the shape of the greenhouse under extraordinary snow loads. I have gone out and cleared 3 feet off the greenhouses in the past that did not collapse them. We didn't have near enough bracing in the greenhouse this year, though and this relatively small storm took us down.

The lucky thing is that the snow didn't entirely crush the greenhouse or kink the wire. If it had been kinked, straightening it without totally disassembling the greenhouse would have been next to impossible.

As it is, the wire is bent, which dramatically decreases the greenhouse's strength. The design depends on the flat panel in a stressed arch. It is curved, but not beyond it's plastic deformation point. So it is trying to return to a flat panel. The internal cords prevent it from returning to a flat panel and transfer the load further down the structure.

Since the greenhouse was not completely crushed and we could still crawl inside, we we're able to lift it back into shape. As we lifted, we tied new cords. After the initial round, we went back and tied more to correct where we were still out of shape. Then again, often untying the first ones. It's a process like tuning a bicycle wheel. You work slowly, making small corrections in many places.

Since the wire had been bent, though, just getting the arch back wasn't enough. We'll have to also need a vertical brace because the wire is no longer straight and won't carry the vertical load. That's the 2x4 on the end. It carries another 2x4 that goes the length of the greenhouse and another post on this end.

We still have work to do, and we won't be starting any new plants in the cold weather. But at least we'll get a jump on spring in the greenhouse.