Friday, October 28, 2011

Burlap: not just for prophets anymore

Here's the thing about winter. Mathematically, if you're a plant, winter is a semi-infinite cold reservoir and a semi-infinite heat reservoir, with 4 or 5 feet of snow in between. The cold reservoir is also very dry, whereas the heat reservoir is hopefully saturated with water; thus the snow not only slows down heat transfer but also prevents loss of water from the heat reservoir. And it's very important for frozen roots to be wet. Dry roots are much more damaged by freezing than wet roots.

Now on a windy seventh-floor concrete balcony, winter is a very small, finite heat reservoir surrounded by an infinite cold reservoir, with just a thin layer of plastic over most of the boundary, except at the top, where the two actually come into contact. If I'm lucky I might get 2" of snow from time to time on the balcony, but it blows away easily.

The problem, therefore, which I tackled last Sunday, is to convert a minuscule uninsulated heat reservoir into a semi-infinite, well insulated heat reservoir.

Hmmmmm...


Step 1: build a heat wall. That garbage can contain 98 L of soil, mostly reclaimed from decommissioned planters. And the burlap bags are a handy acquisition from the hardware store. According to the label, you're supposed to fill them with garden debris, and then soak them with water and leave them out in the yard over the winter, and in the spring you'd have compost. This seems unlikely to happen on my balcony, but certainly the garden debris can hold heat. And as it gets colder, I can progressively saturate them with water, which is an excellent insulant and heat reservoir. So here we see the heat wall, interposed between the cold reservoir and where the plants are gonna be.


Step 2: insulate concrete. Concrete is a great heat reservoir and a very poor insulant. In summer it gets very hot and burns plants, in winter it gets very cold and sucks the heat out of them. So here we have 2" of rigid insulation between the concrete and the planters. Notice that the pansies were still very much alive, this being October 23.


Step 3: profit. I mean, plants. Here you can see the Jungle, cleaned up a great deal, Liu Shao-ch'i in the foreground, and if you look carefully, you can find Peng Dehuai sticking up behind the Jungle. All these are saturated with water, of course. The last thing you want, like I just said, is to freeze your plants when they're dry.


Step 4: build a box. One layer of cardboard has very little R-value, but it will give the whole construct a shape in Step 5.


Step 5: batts. Every construction worker's least favourite insulant. I scored these, as I mentioned before, from a hardware store that was closing for renos and was trying to get rid of every last thing on the lot. So they gave me this big "damaged" bag of sound insulation for $10. Except only the outside was damaged; the batts are just fine. If you're going to insulate your garden with batts, though, here are four things to bear in mind.

1) Batts are not heat reservoirs. They slow the flow of heat, but they don't store heat themselves, therefore, they are not altogether a substitute for soil and snow.

2) Don't squish batts. Their insulating value depends to a great extent on the air they contain. If you squish them, they lose their effectiveness.

3) Wear a N-95 mask, available for cheap from your hardware store, while handling batts. If you think the mask is uncomfortable, you're gonna like having fiberglass dust in your throat even less.

4) After handling batts, have a cold shower and don't rub your skin. The fiberglass dust is very itchy. If you wash in hot water, it will open your pores and be even more uncomfortable, and the more you rub, the more you're rubbing it into your skin.



Step 6: make a burlap tepee. I can't guarantee that this step contributes anything to the survival of my plants, but in my opinion, it gives them some breathing room instead of smothering them with batts. Beside, having bits of fiberglass insulation in your flowerbeds is really unsightly; the burlap makes cleanup easier.


Step 7: more batts. Don't let the picture fool you, however. It looks like I'm putting tons of batts on top and few around the containers; in reality the container is the most important thing to insulate. You're trying to protect the roots, not the leaves.


Step 8: tarp. I was hoping to get an insulated tarp, but the hardware store had none, and given the price of the regular ones, I don't think I'd have paid for an insulated one anyway. The tarp of course provides very little R-value, but it has several other functions: 1) as a wind break; 2) to prevent water loss; 3) to absorb heat from the sun; 4) to keep precipitation off the cardboard; 5) to hold the whole thing together; and 6) to make it visually acceptable. Given that this particular tarp is 10' x 14' and my balcony is somewhat less than 5' x 10', you may be wondering how I managed to unfold and apply the tarp. Well, I'm a construction worker. One of the greatest skills of a construction worker is the ability to persevere when things are very awkward. What's much more amazing is that I managed the whole thing without swearing a single time, since it was Sunday and I try not to swear on the Sabbath.


And now the bigger questions. Is this enough? Is it too much? And how do I get back into my apartment?

As to the first and second, we'll find out in April if anything is still alive. And as to the third, again, I'm a construction worker; I can do these things. The point of building this whole contraption right in front of my picture window was to take advantage of the huge heat loss from said window, as well as get as much of the limited winter daylight as possible. But other than making access and egress difficult, it also blocked said limited winter daylight from getting into the apartment, where the dog and the non-hardy plants like to bask in it. So two hours later, though I had already showered and put on my pjs and it was getting dark, I went back out there and relocated the whole thing six feet away, where it's not blocking the window. It can still get some of the heat from both the picture window and the kitchen window, and some small amount of sun. Hopefully that won't be the difference between life and death.

I must say, I'm quite pleased with it so far. Granted I have no idea whether my plants are alive or dead inside, but it gives me the impression of having a live garden out there, it brought some closure to the summer garden season, and it keeps the place much tidier than having a bunch of planters full of dead things scattered all over the balcony.

The next day, it snowed.

Thus ends, therefore, the 2011 Summer Garden. Thanks for joining me, and stay tuned for the admittedly much mellower adventures of the Winter Garden, and the upcoming 2012 Summer Garden.

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