current outside temperature: 33 degrees, greenhouse temp: 61.2 degrees

Last week, we left off with two cliffhangers… an impending snowstorm and an outbreak of powdery mildew. Did the greenhouse stay warm during our first storm? Have the sage and the tarragon recovered? Let’s see…

The total accumulation last Sunday night was 2.5″ inches. The greenhouse didn’t blow away or collapse (a victory!) and nothing was frost covered inside. We didn’t get the haybales purchased and placed before the storm for two reasons… 1) we wanted to see how the greenhouse would do on its own and 2) perhaps there might be a better alternative.

In theory, haybales placed around the outside base of the greenhouse act as insulation. They cover any vulnerable seams or crevices from drafts as well as act like a barrier against cold winter winds. Our greenhouse was never meant to be air-tight in its design. There are tiny exposed airways around some connector pieces and screws, which is good for ventilation. I hesitated about the bale method of winterization because there are about a dozen plants in our greenhouse that draw light from the bottom sidewalls and the hay bales once placed around the base would block their access to light from that direction. Of course, that would probably only encourage the plants to grow taller, to reach for the light above the bales and towards the roof but the idea of covering up this beautifully airy space with something heavy and dense didn’t seem quite right. In honor of light, we chose to wait and see.

So the snow came and the greenhouse experienced it sans haybales and everything was fine, except for the temperature. The coldest the greenhouse has ever been, even with the heater going at level 3 (the maximum setting) was that night. 43 degrees. Not cold enough for frost to appear but more than twenty degrees away from ideal interior temperatures. This first snowfall was such a good test. We definitely needed to protect it more.

My husband came up with the great idea of a plastic sheet covering the door frame from the peak all the way down to the base. The plastic at the roof was held down with two leftover 2 x 6 pieces of lumber, one on each side of the peak with the board ends resting in the gutters to help hold it all in place. Three treated 4x4s weighted down the plastic at the base. Essentially, he made a makeshift curtain panel for the front door that looked like this…

By covering the greenhouse in this way, it eliminated the draft that comes in around the door while still allowing lots of light to come through. Once this new plastic panel was added, the interior temp went right back up to 65 degrees within an hour. Success!

Until the next night.

Wind got a hold of the plastic and carried the curtain across the yard at some point in the middle of the night. The internal greenhouse temp plummeted straight back down to the low 40s.

Not entirely deterred, my husband set out for a second attempt. This time he stapled the plastic to the treated wood at the base, nailed two shorter boards together to form a wooden peak for the top that mimicked the pitch of the roofline, and then stapled the top end of the plastic to the wooden frame…

And that turned out to make all the difference. For the rest of the week, the plastic has stayed in place and the greenhouse is warm and draft free. To gain entry, we just take the wooden peak down and set the treated wood off to the side and then put it all back in place once we’re done inside. So simple.

Temperatures fluctuations and winter weather aside, luckily the greenhouse plants didn’t seem to be affected by all these up-and-down changes. The sage and tarragon were still flocked with powdery mildew so they got a second spray of the organic fungicide. The tarragon responded to this extra care and attention by slowly unraveling its first flower…

The marigolds have been thinning themselves out one by one since they arrived in the greenhouse, so they got repotted to a smaller container. If I had to peg any of the summer flowers that I thought would do best in the greenhouse it was the marigolds. They were such hardy growers in the garden from spring to fall, so I was surprised to see them losing leaves, drying out and getting long and leggy in the greenhouse. Hopefully, this new home will encourage them to fill out more around the middle.

On the growth spurt front, the geranium leaves tripled in size…

the broccoli grew by another inch…

the spicy Santaka pepper seedlings put out a whole new layer of leaves…

and our lone bell pepper seems to grow bigger by the minute…

Between seeing the greenhouse outlined in snow early in the week and then hearing the tinkling of raindrops on the roof at the end of the week, I can understand now why Philip Johnson built and loved his Glass House so much.

While working on that and the neighboring Brick House, Philip mentioned being overtaken by waves of emotion for certain details during the design process. He was talking about archways and vantage points and shapes that felt like hugs, but I loved that he used the word overtaken to describe his attraction to the space and his ideas in it. That’s exactly what it feels like to stand in the greenhouse. To be overtaken by nature, by light, by warmth, by possibility, by protection. It’s no wonder plants thrive in such an environment.

As we work through renovations on the 1750 House during these fall and winter months, oftentimes the greenhouse is the warmest, quietest, calmest place to be. The polycarbonate walls muffle man-made sounds from the environment but oddly amplify the sounds of surrounding nature like birds singing in the trees or leaves whirling around on the ground. The bright light, even when the sky is cloudy and threatening with rain or snow, illuminates all the details on every leaf, on every petal. Possessed of an ever-evolving scent similar to warm tea the whole space changes aromatically day by day depending on what’s in bloom. And the heater – that warm little hug of a heater wraps everything up like a cozy sweater on the coldest of days. I used to think The Glass House was such a vulnerable piece of art, exposed, and unsettling in its lack of privacy. But now I see that what Philip created there was a love letter to the senses. This greenhouse is much the same. Plastic curtain panels and all.