If you’ve read the blog before, you know that we love our high tunnels, and we strive to be a four-season farm. Since getting our first tunnel 3 years ago, we’ve been continuously improving our growing practices to have fresh produce available every week of the year.
One major gap was the early spring season, particularly in March, April, and early May. In our region, this time of year is too early to really have anything grow outside. But we’ve read that our high tunnel can give us fresh produce several weeks earlier in spring. This year, we’re putting that to the test.
In 2026, we’ve put real effort into growing some crops in our tunnel specifically for early spring harvests. Our goal is to have data for future crop plans (and obviously salads in March!). Here’s what we did and how it went!
Crop Selection And Timing
In reality, our spring experiment had two goals. The first was to see how early we could harvest things that weren’t planted the previous fall. The second goal was to expand our variety for our first couple of CSA shares and markets in mid-May. Rather than simply having salad greens and radishes, we wanted to see if we could get a few more crops to mature in the tunnel. That way, we could add variety to the greens that are usually ready by mid-May outside.
For the early crops, we chose lettuce, romaine, arugula, spinach, cilantro, and parsley. We sowed the lettuce and romaine in soil blocks way back in late January, and kept them from freezing for 4 weeks before transplanting. These were the very first crops we transplanted in 2026.
After they were transplanted, we had to make sure they were double-covered with row cover on cold February and March nights. Arugula was direct sown, basically as soon as we got enough warm days in a row to plant and irrigate the seeds. This was the very beginning of March, but we might be able to go earlier depending on winter weather.
Unfortunately, our very first sowing of arugula froze and died on a night we forgot to double-cover it. But each sowing after that was successful, and we had arugula to harvest at the very end of March.
For spinach, we sowed that in soil blocks and transplanted it in mid March, for a harvest in early April. We definitely think we could start spinach earlier, since it’s very hardy. Next year, we’ll try to start it alongside lettuce.
For those mid-May crops, we chose things that we can typically harvest in late May or early June outside. This year we went with carrots, beets, and green onions. Turnips, snap peas, bok choy, and kohlrabi are also good candidates, but we were limited on growing space.
We direct sowed our carrots in early March. I think that is probably about as early as I would want to go. Carrots take a long time to germinate and must be kept moist, which is difficult in a cold spell.
Along with the carrots, we transplanted beets and green onions around the same time. In the future, we will probably wait longer on the beet, since we had a colder night do some serious damage, even after double covering.
Spring Harvesting
For early greens, the verdict is that arugula and spinach will probably be our earliest to mature. We started harvesting both in late March, and it’s probably possible to go a couple weeks earlier.
Lettuce seems like it will probably be ready to harvest in early to mid-April in the best case scenario. For all of these crops, harvests are about 4 weeks earlier than the earliest outside harvest, which matches what most folks report from their high tunnels. Those 4 weeks may not seem like much, but they make a big difference for our restaurant customers!
For the mid-May harvest crops, the jury is still out – we’re writing this in mid-April – but so far, so good. If the 4-week timeframe holds for these crops, we should have fully mature beets, carrots, and green onions for week 1 of our CSA. Having that extra variety for those first couple of weeks will be great for our CSA customers!
High Tunnel Plans Beyond 2026
While this spring hasn’t been entirely an experiment, we didn’t plant the variety or scale of crops that we’d ultimately like to. This is due to the relatively small space inside our two high tunnels. We hope to add a third, larger high tunnel that would let us achieve the scale we want.
In the future, our crop plan will enable us to have fresh harvests quite literally year-round. In spring, we’ll have overwintered beds of greens that we harvest from January through February and March, in enough quantities to supply restaurants and potentially a small winter CSA. Then in late March and into April, we’ll switch from greens that are overwintered to ones that we planted out early in the year.
We’ll also have space to dedicate to early plantings of several crops to enhance our variety through the early parts of our CSA and market season. Basically, our high tunnels will take us from having absolutely nothing to harvest until the beginning of May, to a vibrant palette of fresh produce from the beginning of the year right through summer.
All this with simple, unheated high tunnels! Combining tunnels with crop plans and precise timing makes our farm more sustainable, resilient, and joyful!
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