Greenhouse Re-Upholstery

I guess the fact that I am about to complain about our greenhouse speaks to the privileged life we lead here at the Golden Rule Garden, but those who have seen it will agree – it is almost worse than no greenhouse at all. See Exhibit A above: the original skin, fiberglass. No doubt wonderfully durable and transparent for the first couple of years, but you can see to what level it has sunk. Yes, technically it does let in light, but probably around 50%, and that is abysmal for a greenhouse. Does anyone know the word “leggy” as applied to plants? Here is Exhibit B: seedlings which, though given plenty of water and excellent flat soil, could still arguably be described as “languishing” in their relatively dark dungeon. Exhibit C, parts one and two, are full-grown amaranth plants inside and outside the greenhouse. As you can see by the little reddish blotches towards the top of the sea of green, the ones inside are reaching for the sun, putting all their energy into nearly eight-foot stalks with tiny seedheads. The ones outside are short in comparison, maybe 4.5 feet, but have great, full seedheads. I rest my case. The defense might add that the greenhouse does provide enough warmth for the lemon trees to survive and that swiss chard sure seems to thrive, but I, the prosecution, would interject that, yes, the chard does fine until the aphids get tired of their first love, the fava beans.

But let’s not bicker about it. The truth is that our greenhouse is not ideal, but we must make the best of it. And the best of it is the south end, where a few years ago a seedling room was created. Set against the southwest corner, interior walls and lowered ceiling were framed and covered in plastic to retain heat, and the floor was covered in hardware cloth to keep miscellaneous varmints out. It works great to collect and retain heat, even in January, but does a poor job in the sunlight department.
The point is that we want strong, correctly proportioned seedlings, not weak, leggy wastrels. That’s where a little motivation and all the wood, plastic, and screws one could wish for come in. We have been thinking about taking the roof off the whole dang structure and covering it in plastic, but that seems to be a long way off. The real urgency was the seedlings, and so I got permission to take drastic measures on the west side of the south end.
Step one was to, well, take a picture for posterity, of course! But then to remove all of the fiberglass. I’ll let you know, for those who haven’t experienced it yet, that deteriorating fiberglass leaves shiny little fibers all over your hands. I guess the resin breaks down and stops holding it together. Anyway, I got the gloves out after I realized that fact. This was the simple and fun part, first because it got a lot hotter after about 10 am (on the south side of a big structure), second because it’s always a lot more fun taking things apart than putting them back together. So the second photo in the series is the naked seed room.
The upper section of fiberglass didn’t need to be removed, but I wanted to tuck the plastic sheeting under it, so I climbed up above the seed room inside and screwed in scrap wood to prop the upper section out from the wall. You can see that in the third photo. Also subtly present in this photo is the absence of the sliding door rail, which, though heavy and unwieldy, was completely in the way and had to be removed temporarily. So did the windows.
The third photo also showcases the first layer of plastic. I stretched it as tightly as possible simply for the sake of being neat and tidy since it will not be subjected to the stresses of wind like the outside layer. While one layer would be enough to protect the seedlings from birds, heavy rain, and fierce winds, it would not insulate nearly as well as two. Kind of a primitive double-paned energy star window, but we’re short on caulking and argon, so we went with the easy way.

I put the first layer of plastic directly on the frame of the greenhouse, then screwed 1x2” boards over it as the spacers between plastic. Nails would have worked as well and been cheaper, but I don’t know how long this greenhouse is going to last. I don’t want folks to be cursing my contribution when it comes time to disassemble.

The last photo shows the final product. The second layer was stretched as tight as possible, and ¼” boards were nailed along the studs. This way any flapping in the breeze will be kept to a minimum, and the thing will last longer. All the finishing boards are redwood, which is kind of a treat. Too expensive in many areas to be practical, these specific boards are reused from a recently renovated building that is over sixty years old. Redwood is local to us, and can be farmed responsibly, though due to the age of these boards it is possible they are from old-growth trees. Redwood is known for its slow deterioration, to which these particular boards attest.
An important point here: this project does not express our walk of sustainability, just so nobody thinks I'm completely ignorant of this point. Plastic and fiberglass are not, as of this writing, supplies which can be created without a lot of toxic processes. And, clearly, they are not made to fill their purpose for more that five or ten years, after which time they will be junk. We will need to be much more insightful to devise sustainable tools for season extension.
I’m not a great finisher, so this project was a real trial for me. The bulk of it was simple to execute, but the final touches of trimming, tucking, filling gaps and fine-tuning were a bit much. Thus the homage to those, like my friend Bobbi, who have a flair for sharp re-upholstery.
In the end we have a seed room that will be worth the effort others have already put into it, because now the fortress lets in light!