OUR FIRST WINTER WITH THE HIGH TUNNEL - EASTERN MA ZONE 6B

I was hoping for a mild season for our high tunnels first winter- but that wasn’t quite the case. Our coldest temperature got down to -3F 01/31/26. Several polar vortex events starting in early December brought single-digit nights, and multiple blizzards in January and February left us with storms dumping over two feet of snow and 60mph wind gusts.

But - the high tunnel survived the blizzards, and the crops inside survived the cold. Out of everything we planted, nothing experienced significant cold damage. I could tell sensitive new growth on the sweet peas suffered a bit on the coldest nights, but they bounced right back come spring.

The goal of the high tunnel is to strategically utilize the space within to overwinter the most high quality, profitable spring crops so we can hit Mother’s Day holiday, and benefit from a longer growing season. I want crops that will not only survive winter in the high tunnel, but benefit from being in the tunnel with earlier bloom times, and higher quality/longer stems.

Qualities I am looking for in our high tunnel crops:

Can survive the cold (our tunnel is unheated)
Will produce a higher quality bloom in the tunnel than a field grown counterpart
Financially worth the space it takes up in the tunnel (high demand flowers)
Will bloom earlier than a field planting (Ideally in time for Mother’s Day)
Will bloom by June so we can also get in a crop of summer planted annuals before planting for winter again in late September.

Our Method

I ordered most plugs from Farmer Bailey. They have great growing guides for all the crops they sell on their website. Between Farmer Bailey’s ‘Grow Guides’ resources, and Johnny’s Seeds ‘Overwinter Cut Flower Trials’ resources, I was able to create a list of flowers that should survive winter in the unheated tunnel, and bloom early enough to meet Qualities #4 and #5.

I planted most crops in the tunnel in Mid September, excluding ranunculus and tulips which I put in closer to November. I ordered most plants as plugs, summer is a very busy time and it is more cost efficient for me to buy plugs than to start my own seeds this time of year. I did start seeds for plants I could not order as plugs (ie the sweet pea).

I watered when needed up until our water cut off in early November. November through April our tunnel did not get watered, as the water on the property is off to ensure no pipes burst. This fall I will bring in an IBC tank for the tunnel- I do think the tulips and ranunculus in the tunnel would have benefitted from more water, especially in March when they were putting on active growth but the property’s water was still off.

Whenever night temps dropped below 28 I would cover with one layer of AG 70 frostcloth. When night temps dropped below 20, I would cover with two layers of frost cloth- one layer of AG 70 and one layer of whatever else I had on hand- usually AG 50. Even on the coldest nights, when we reached single digits outside, the frost cloth kept the temperatures at/above 24 degrees. There was no point in time when the soil in the tunnel froze solid, even during prolonged cold periods. From early December- early March the rows in the tunnel pretty much always had a layer of frost cloth on them. I was not on site every day to cover/uncover rows and they were fine.

The only crop loss we experienced was due to pest pressure (voles on the ranunculus and aphids on the sweet peas). No crops seemed particularly stressed or damaged from the cold.

Winter 2025-2026 was a big trial year- I planted smaller quantities of a lot of different crops to think through what would meet the earlier outlined qualities I’d want from high tunnel flowers.

*Oct. 8 2025- most plugs are planted. Tulips and ranunculus not quite yet in the tunnel.*

Our Results - Spring 2026

We trialed 19 crops in the tunnel and their overall impressions for this season. Some crops, such as the dianthus, performed well in the tunnel and were even better than their field planted counterparts, however they just did not generate enough wholesale demand to be worth the space. Others, like the cynoglossum, performed well but did not bloom early enough to be worth it. I can have field grown cynoglossum by mid June with an early enough planting- I don’t mind waiting just a few more weeks for this crop.

Dianthus ‘Sweet Coral’
Success? Yes
Bloom Time: 5/8-5/20
Better Than Field Grown? Yes- earlier, taller blooms
Notes: Not high demand
Grow Again? Not in the tunnel

Dianthus ‘Amazon Neon Cherry’
Success? Yes
Better Than Field Grown? Yes- but not by much
Notes: Not high demand
Grow Again? Not in the tunnel

Digitalis ‘Camelot Lavender’
Success? Yes
Bloom Time: 5/6-5/18
Better Than Field Grown? Yes- Camelot doesn’t overwinter well in the field
Notes: Incredible
Grow Again? Yes- way more for 2027

Digitalis ‘Suttons Apricot’
Success? Yes
Bloom Time: 5/18-5/25
Better Than Field Grown? A bit- but not much
Notes: Small sample
Grow Again? Yes- but would also be fine in field

Sweet Pea ‘Elegance Series’
Success? Yes
Bloom Time: 5/15-6/1
Better Than Field Grown? 6 weeks earlier
Notes: Manage aphids
Grow Again? Yes

Sweet Pea ‘High Scent’
Success? Yes
Bloom Time: 5/15-6/1
Better Than Field Grown? 6 weeks earlier
Notes: Manage aphids
Grow Again? Yes

Sweet Pea ‘Lunar Blue’
Success? No
Bloom Time: N/A
Notes: Lost to aphid pressure. Beautiful.
Grow Again? Would try again

Campanula Champ. II Series
Success? Yes
Bloom Time: 5/25-6/16
Better Than Field Grown? Yes- so much taller
Notes: Incredible
Grow Again? Absolutely

Bells of Ireland
Success? No
Bloom Time: 5/20-6/1
Notes: Lost to vole pressure
Grow Again? Would likely do in field instead

Snapdragon Double Legend Pink
Success? Yes
Bloom Time: 5/10-5/25
Better Than Field Grown? Yes- so tall
Notes: Highest quality I have grown
Grow Again? Yes- high demand

Snapdragon Chantilly Salmon
Success? Yes
Bloom Time: 5/10-5/25
Better Than Field Grown? Yes- so tall
Notes: Highest quality I have grown
Grow Again? Yes- high demand

Snapdragon Cool Orange
Success? Yes
Bloom Time: 5/10-5/25
Better Than Field Grown? Yes- so tall
Notes: Highest quality I have grown
Grow Again? Maybe

Snapdragon Antibes Red
Success? Yes
Bloom Time: 5/15-5/30
Better Than Field Grown? Yes- so tall
Notes: Highest quality I have grown
Grow Again? No- not high enough demand

Cynoglossum ‘Mystery Rose’
Success? Yes
Bloom Time: 5/20-5/30
Better Than Field Grown? Taller and earlier
Notes: Not early enough- would be happy with June blooming field planting
Grow Again? Not in tunnel

Ranunculus ‘Amadine’ Series
Success? No
Bloom Time: 4/15-5/15
Better Than Field Grown? Tall, strong, high quality stems with huge blooms. Much earlier than field
Notes: Lost 80% to vole pressure
Grow Again? Yes- with more protective measures

Orlaya ‘White Finch’
Success? Yes
Bloom Time: 5/10-5/25
Better Than Field Grown? Yes- so tall
Notes: Incredible
Grow Again? Yes

Tulip ‘Exotic Emperor’
Success? Yes
Bloom Time: 3/21-3/28
Better Than Field Grown? Much earlier
Notes: Very successful- needed additional water brought in
Grow Again? Absolutely

Tulip Double Early ‘Dreamer’
Success? Yes
Bloom Time: 3/31-4/6
Better Than Field Grown? Much earlier
Notes: Beautiful, but too short for high tunnel real estate. Fine for field
Grow Again? Too short for tunnel

Tulip Double Early ‘Columbus’
Success? Yes
Bloom Time: 3/31-4/6
Better Than Field Grown? Much earlier
Notes: Very successful- needed additional water brought in
Grow Again? Absolutely

December 5, 2025

January 8, 2026

February 10, 2026

March 16, 2026

April 10, 2026

May 15, 2026

Stand Out Crops For Spring 2027

Digitalis Camelot/Dalmation Series

These have not overwintered for me well in the field. High tunnel grown Digitalis were very high quality (so tall!) and one of the earliest blooming plants out of the tunnel. They really elevated our Mother’s Day bouquets, and were very popular with our floral wholesale clients. No vole or pest pressure.

Champion Series Campanula

They do not bloom that much earlier than field campanula since they are day length sensitive, BUT they are so much taller and more floriferous than field planted campanula. They seem like a different crop in the tunnel. The stems are over 3’ tall, loaded with blooms, and produce multiple high quality, usable stems. High florist demand, blooming in June when a lot of other things are either fizzled out or still warming up, and can store well in the cooler for a while. No vole or pest pressure.

Snapdragon Chantilly/Legend/Other Specialty Series

All snapdragons performed well in the tunnel and outcompeted field plantings in terms of timing and stem quality. However, ‘specialty’ snaps had much higher demand than standard snapdragons. I will likely still grow some kind of standard snapdragon in the tunnel, but the Chantilly series and various double series have proven to be more popular with my wholesale clientele and thus will take priority.

Snapdragons are also densely planted and highly productive, which makes them all the more deserving of high tunnel space.

Tulips

Tulips performed well in the tunnel, and bloomed earlier than their field counterparts by about 3 weeks. Tulips are also a densely planted crop- I fit about 2,000 tulips in a 4x20 space in the tunnel. Tulips are a high value, high demand crop for us, and they can store in our cooler for a few weeks.

I will expand more space in the high tunnel for tulips for Spring 2027. I also think I will be able to start our farm’s Tulip CSA earlier this way! Between the high tunnel planting, a low tunnel in the field, and then our general field planting of tulips, our 2026 tulip season ran from 3/25-5/10.

Two notes- tulips need a lot of water at planting, and during active growth. I did have to haul in water for the high tunnel tulips, which was a bit of an ordeal. Having water on hand in an IBC tank inside the tunnel will allow me to water them in the spring with less hassle.

I also will be planting precooled 5c tulip bulbs in the tunnel, to ensure they get enough chill time.

Tulips also finished in perfect time to put lisianthus in their space, ensuring they get a few cool weeks to establish before the heat sets in.