Quirky Alaska Greenhouse Tomatoes

I have to admit, I didn’t like tomatoes before my husband built a greenhouse for me 6 years ago. He grew up on the sweet tomatoes his father grew in California and compared all others to those. I planted them initially for him, then I tasted my first homegrown cherry tomato and I was hooked.

My unheated greenhouse is an 8×8 structure with clear Tuftex corrugated polycarbonate roof panels. My husband wanted panels that wouldn’t yellow and would allow the most light possible to pass. There is a 70 CFM bathroom exhaust fan above the door on the east wall and a 2 ft by 3 ft window on the west wall. The window in the door can be raised to allow air through the screen. On the inside, each side has elevated and raised beds, 16 inches deep, 24 inches wide, and 7 feet long. Each box has drainage to a slightly angled base that drains the excess water into a bucket that I then reuse. I monitor the temperature with a thermometer that records the highs and lows over the past 24 hours. Some days it stays the ambient temperature and some days it gets in the 90’s depending on cloud cover.


My greenhouse gardening focus is on the tomatoes, even at the expense of the rest of the “easy keepers” outside. I’ve bought tomato starts and have started my own from seed. The plants I’ve started myself always seem to grow bigger and produce more that the nursery bought starts, though growing them in the greenhouse seems to intensify certain problems. I dubbed 2014 the Year of the Fungus; powdery mildew had me spraying Neem oil twice a day just to keep it under moderate control. This year I added a window fan on a timer to help the exhaust fan with air circulation so we will have to wait and see once the rainy season starts. Another year I truly believe my greenhouse was Ground Zero for aphid production. I think the lady bugs died from overeating.

Anyone who has grown tomatoes in Alaska knows the result of the amount of hard work that goes into growing a tomato is directly proportional to how many fingers you can cross at a time and how many tomato prayers you can think of. I properly plant the tomato plants, mulch, water and fertilize. I buy the lady bugs for the aphids and I keep everything organic. And each year they do great — until they don’t. I’ve tried different fertilizers, different watering times, cooler water, warmer water, fast fans, and slow fans. I Googled and I read books and followed all the advice.

The tomato plants start out just lovely, rich dark green leaves and bright yellow flowers that turn into perfect little green cherry tomatoes. I see them every day so I don’t notice the leaves lightening to pale green, then yellow, then brown. The fruits are slow to ripen and the plants turn spindly. I don’t see it until my husband points out just how sad they look. I grudgingly admit my husband finally figured out the problem; sometimes it’s hard to see the tomatoes through the tomato plants so to speak. He thought the plants looked sunburned, like they get if not hardened off appropriately.     Even though it was the end of July and they have been in the greenhouse since mid-May. Even though tomatoes are supposed to love sun. Even though the tomato varieties I planted were chosen for heat and sun tolerance. So, I agreed to tack up white sheets on the south-facing wall “just to see” and within 7 days the tomato plants were back to rich green and full flowers. That’s not how tomatoes are supposed to work but it did. He was right. My tomatoes like a bit of shade.


This year, I removed the sheets and I placed a white vinyl roll-up shade, thinking that it would be easy to roll up on cloudy days, and nicer to look at than sheets. However, the tomato plant leaves get stuck and pull on the entire plant. Now that the plants are big, I cannot easily reach the string to roll the blinds. Next year I will try thin vertical slat blinds that might not bind the leaves as much and will be easy to reach. The tomato plants are thick and tall, have rich dark green leaves, lots of flowers and lots of baby tomatoes. They look very happy in their shade!


As great as the tomato plants look this year, I’m hoping only to tweak a few things to find that perfect sweet spot of greenhouse tomato gardening. But as we all know, it’s a fluid thing, this growing of plants, and next year we might not have any sun and only rain like a few years ago. I will continue to add or remove things as trial and error and education dictates, each year thinking, “this is it, I’ve got it,” until the next year when more ideas or problems surface. That’s part of the fun, figuring out the puzzles of the year and seeing if it will work next year.

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