Winter Greenhouse Growing: Cold-Hardy Crops That Thrive
- greenhousekits1
- 7 minutes ago
- 3 min read
One of my favorite things about a well-built greenhouse is that the growing season doesn't really have to end. We build and sell a lot of our kits specifically for year-round growing, and winter is honestly one of the best times to put that to use. Some of my favorite crops actually taste better after a little cold, and a solid greenhouse (even one without heat) gives you enough of a head start on the season that you can keep harvesting fresh greens long after everyone else's garden has gone to mush.
If you've never planned out a winter garden in your greenhouse before, here's what actually works, what to plant, and a few things I've learned over the years helping customers set theirs up for year-round growing.
What Winter Greenhouse Growing Actually Looks Like
A greenhouse doesn't need to be heated to keep plants alive through winter — it just needs to block wind and hold onto the sun's warmth during the day. On a sunny afternoon, even an unheated greenhouse can run 15-20 degrees warmer than the outside air, and that buffer is usually enough to protect cold-hardy crops from a hard freeze.
If you're in a colder climate or want to grow more tender crops through the winter, it's worth pairing this with a little supplemental heat — I covered exactly how to do that affordably in How to Keep Your Greenhouse Warm Without Breaking the Bank. But for the crops below, most growers don't need to run a heater at all.
The Best Cold-Hardy Crops for Winter Greenhouse Growing
These are the crops I recommend to customers every fall because they hold up beautifully in cold temps and actually get sweeter after a frost:
● Spinach — about as cold-hardy as it gets, and it just keeps producing
● Kale — frost makes it sweeter, not worse
● Lettuce and mesclun mixes — pick a cold-tolerant variety and keep it coming
● Swiss chard — slow and steady all winter long
● Arugula — fast-growing, so you can keep reseeding through the season
● Bok choy and tatsoi — great cold-weather Asian greens that mature quickly
● Carrots, radishes, and beets — root crops handle cold soil just fine
● Green onions, parsley, cilantro, and chives — herbs that don't mind the chill
A lot of these are quick to grow, which is exactly what you want in winter — shorter days mean everything slows down a bit, so smaller, fast-maturing crops give you the best return.
Tips for Keeping Winter Crops Happy
● Get plants started 6-8 weeks before your first hard frost so they're established before the coldest weather hits
● Keep a layer of frost cloth or row cover on hand for the coldest nights — it's cheap insurance
● Water less often than you would in summer, and water earlier in the day so leaves aren't wet going into a cold night
● Still crack the vents on sunny winter days — a greenhouse can overheat even when it's freezing outside
● Don't expect summer speed. Winter growth is slower, and that's normal, not a problem
Do You Need a Heated Greenhouse for This?
For the crops on this list, no — a well-built greenhouse or high tunnel does the job on its own. That's actually one of the biggest advantages of our Four Season Kit, which is built to hold up through real winter weather without needing extra heat for hardy crops. If you want to branch out into more tender vegetables later in the season, that's when a small heater starts to make sense.
A Few Final Thoughts
Winter greenhouse growing isn't about fighting the season — it's about picking the right crops and letting the greenhouse do what it does best. I always tell folks: start small your first winter, see what does well in your setup, and build from there. Before long you'll be the one harvesting fresh greens in January while everyone else is scrolling through seed catalogs.
If you have questions about which kit setup makes the most sense for winter growing in your area, give us a call or shoot us an email — we answer our own phones, and we're happy to help you plan it out.
Happy growing!
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