Show Transcript

0:00Hi guys, I'm here at Bountiful Blessings Farm with my dad, John, and we're going to be talking about some things to take into consideration when purchasing a

0:07high tunnel. You have purchased probably a few 10 or 12 high tunnels at this point. And so from a grower's

0:16perspective, what are some of the key things that you consider when purchasing a new tunnel?

0:24We should say that a lot of your tunnels are not from Farmer's Friend. Yeah, that's true. Uh,

0:32also a lot of your tunnels were purchased before we were selling tunnels, but that's true, too.

0:40I I think in my mind the biggest thing is shape.

0:45I really dislike the quanset shape except in the caterpillar tunnel. it it's fine for the caterpillar tunnel,

0:56but for a greenhouse,

0:58for reasons that I talked about in other videos, the quite shape is not good in my opinion. I like something

1:07with straight sidewalls so you can walk along the edge at least 6 foot high. So,

1:14that shape is is something I definitely am looking for. the the Gothic shape sheds snow much easier, much better. Um,

1:24then the second thing I think I would look at is the the thickness of the steel. Mhm.

1:30You know, there's a lot of variation on that and um you want something a tunnel

1:38is not a place to scrimp money. I I feel, you know, you may end up paying

1:44um more than, you know, the the cheaper options out there, but you want

1:52something that you're not going to have to replace in a few years because the bow's bent or whatever. Mhm.

1:59So, tunnel thickness, I mean, the the bow thickness,

2:03I don't know. The the smaller the number, the thicker, right? The thicker it is. Yeah. Yeah. So, um,

2:1114 gauge is pretty standard on on a lot of larger high tunnels, and that's what we use for all of our tunnels except for

2:20the classic Caterpillar tunnels. We do 17 gauge, but yeah. And and we have had

2:30some of those bend in the wind, so if I were replacing them, I would definitely get the 14 gauge. Yeah, it's it's

2:40significantly stronger. Uh almost double the strength. Um so yeah, lower lower the gauge number, the thicker the the

2:48material. So that's critical. Um bow spacing is another important thing. And that varies depending on what part of

2:57the country you're in. If you get a lot of snow, you want to go with the 4ft spacing, bow spacing.

3:05Um we don't feel the need for 4 foot. Um our tunnels are either five or six feet and that's worked fine for us.

3:18But then um your uh what's the word for your the trusses? Trusses.

3:28Um I think it's good to have trusses on your bows.

3:33Every bow. Well, I mean, for a wide tunnel, for a 30 foot wide tunnel, I Yes,

3:41we lost two tunnels. I'll just tell you one of our heartbreaks. We lost two

3:46tunnels um to ice and I still think it

3:52was um a manufacturing or an engineering defect. the the the trusses were up too

4:01high and and they they bent right at the edge of the truss.

4:09Ice storm took them out. Huh.

4:10Yeah, it was. I mean, we were shocked to be honest. We didn't think it was enough

4:16to cause any issues. So the fact that two tunnels came down in that in my

4:24opinion was an engineering um mistake. Interesting.

4:32Uh so but I do believe in trusses.

4:36What about size of tunnel and you know how what what size tunnel would you recommend when people are getting started?

4:43I mean the biggest you can afford.

4:46That's what I would recommend. Um but but without scrimping on quality because you can buy

4:53pretty big tunnels uh for a small price but they're just not going to be quality.

4:59Yeah. And I've seen those tunnels come down. Um I I have friends that you know

5:07they're just trying to get some covered growing space. But yeah, just this last winter had a friend up in Indiana lost

5:16two tunnels. But they just weren't they they were cheap tunnels. Yeah.

5:22And um you don't want cheap tunnels. Yeah. Wind bracing is another thing. You know,

5:30we had a tunnel got one of our early tunnels didn't have any wind bracing on the corners. I think that's really important.

5:41Um number of pland. I don't know how important that is, but it makes sense to

5:48me that the more plland sturdier it's going to be. Yeah.

5:54So, those are de uh all steel. You know,

5:59that's a mistake we made in the early years. We use wood on the sides and end

6:06walls and stuff. And I mean, I know some of your tunnels have wood. Um, on the end walls, it's not as bad,

6:14but on the sidewalls because you've got moisture coming off

6:20the the roof of the hoop house. Um, our we didn't use treated wood. We didn't

6:28want that anywhere near the soil. And that wood lasted maybe 2 or 3 years. You have to redo it.

6:38Yeah. Yeah. It's a lot of pain for sure.

6:41So all steel is the way to go in my opinion.

6:44Yeah, for sure. Cool. Well, thanks for those thoughts. Um there's so many things to take into consideration when

6:51you're looking to purchase a tunnel. And uh I will say too just you know when we started selling tunnels the caterpillar

7:00tunnels especially we had in mind this goal of selling just the the most inexpensive but yet still fairly quality

7:07tunnel and we sold a lot of them but we have had in the early days and a lot of those 17 gauge structures especially

7:15when we started doing 17 gauge gothic structures that we started seeing more damage from storms and stuff and we we didn't like that. you know, it's

7:23devastating for growers. And so, we've even redone a lot of our kits to include 14 gauge standard across the board on on

7:31almost all of our kits except for the classic Caterpillar tunnels. And um it's just not worth trying to save a few

7:41thousand dollar, you know, um if you lose the tunnel, you're going to lose a lot more than that in lost crop. Um so,

7:48I think it's it's good hearing that coming from you.

7:52um just go ahead and invest in something that you have a high level of confidence all metal kit ideally um metal baseboard

8:01and then from a purchasing standpoint you know be looking at what's included in the kit. A lot of greenhouse companies like to kind of put out uh a

8:10real compelling price initially but then when you get into it you realize it doesn't come with a bunch of stuff. It doesn't come with rollup sides. it does,

8:16you know, all of these things have to be added on uh to even get a functional product. Um and then another really

8:24important thing if you're thinking about building it yourself, look at the instruction manuals, the supporting documentation, the videos, cuz it's not a

8:32most of these tunnels are not um it's not a beginner uh DIY project, you know,

8:38and so you really want to look at the supporting documentation that comes with it. If you've never built one before,

8:45you get this big pile of metal and it can be a bit overwhelming.

8:50Um, once you've done a few, they're all pretty much I mean, you know, they're pretty similar, so it's not a big deal,

8:58but for that first one or two, having really good instructions is key. Yeah.

9:05Yeah. Instruction manuals and videos and stuff, that's important to Yeah. to have a good experience for sure. So, any other final thoughts on high tunnel purchases?

9:20You can never have too many high tunnels. That's my final thought. You know, we're always every year we're putting up a new one, it seems. Um,

9:31just the weather is just getting more and more crazy.

9:36And like I said in a previous video, if we hadn't had high tunnels, as many high tunnels as we have this spring, we would

9:45have been up a creek because we had so much rain. Yeah, that's it's true. Um,

9:52you look at I I was we were recently talking about the Netherlands and the incredible production uh vegetable

9:58production there and and they contribute their their success largely to tunnels.

10:04So, um, it's definitely something that needs to be taken in consideration hopefully early on in your farming career. Uh, invest in some good quality tunnels and it will serve you well.

10:14This tunnel is 25 years old. Yeah. And going strong.

10:22All right. Well, I hope this information has been helpful and until next time, happy growing.

10:28[Music]

How to Choose a High Tunnel for Your Market Farm: A Buyer's Guide

By Jonathan Dysinger and John Dysinger

Updated on

![][image1]https://www.farmersfriend.com/learn/choosing-high-tunnels-for-lasting-success

# How to Choose a High Tunnel for Your Market Farm: A Buyer's Guide

By Jonathan Dysinger

When choosing a high tunnel, prioritize a Gothic or straight-sidewall shape over a Quonset, 14-gauge steel bows at minimum, all-metal construction (including baseboards), and trusses on every bow for wider tunnels. Buy the biggest quality tunnel you can afford — but never sacrifice structural integrity to save money, because losing a tunnel to a storm costs far more than the price difference between a cheap kit and a good one.

A high tunnel is one of the biggest investments you'll make on your market farm. It's also one of the most impactful. The right tunnel will pay for itself in extended seasons, weather protection, and crop quality for decades. The wrong one can come down in a storm and take an entire season's income with it.

My dad, John Dysinger, has purchased 10–12 high tunnels over his 27 years farming at Bountiful Blessings Farm — many of them before Farmers Friend even existed. He's built them, maintained them, and lost a couple to ice storms along the way. In a recent video, we sat down to talk through what he looks for when buying a tunnel, what mistakes to avoid, and what we've learned from both good purchases and bad ones.

If you're shopping for your first high tunnel — or your next one — these are the considerations that matter most.

What Is a High Tunnel?

A high tunnel (also called a hoop house) is a walk-in, semi-permanent structure covered in greenhouse plastic that protects crops from weather, extends your growing season, and gives you far more control over your production environment. Unlike a heated greenhouse, most high tunnels rely on passive solar heating and ventilation rather than mechanical climate control, making them much more affordable to operate.

For market farmers, high tunnels are a game-changer. As my dad puts it, "You can never have too many high tunnels." The weather is getting more unpredictable every year, and without tunnel protection, a single stretch of heavy rain, late frost, or hail can wipe out weeks of work. The oldest tunnel at Bountiful Blessings Farm is 25 years old and still going strong — that's the kind of return on investment a quality tunnel delivers.

What Shape High Tunnel Should I Buy?

This is the single biggest factor in my dad's mind, and it's the first thing he evaluates.

Avoid the Quonset shape for high tunnels. The classic rounded-arch Quonset is fine for a caterpillar tunnel, but for a full-size high tunnel, it has real drawbacks. The curved sidewalls mean you lose usable growing space along the edges, and you can't walk upright near the sides of the structure.

Look for straight sidewalls at least 6 feet high. This gives you full access along the edges of the tunnel — you can walk, work, and harvest without crouching. It also means your beds along the sidewalls are fully productive, not wasted space.

A Gothic peak is ideal. The pointed top of a Gothic shape sheds snow and ice far more effectively than a rounded arch. If you're in an area that gets any winter precipitation at all, this matters. My dad has seen firsthand what ice accumulation can do to a tunnel that doesn't shed it properly.

The Guardian High Tunnel is a good example of this design philosophy — 6.5-foot vertical sidewalls with a Gothic profile.

What Gauge Steel Should a High Tunnel Be?

Steel thickness is critical, and it's one of the easiest places to evaluate tunnel quality.

Steel gauge works inversely — the lower the number, the thicker the steel. 14-gauge is the standard you should look for on a full-size high tunnel. It's what we use on all of our tunnels at Farmers Friend except the classic caterpillar tunnels, and there's a reason: 14-gauge bows are nearly double the strength of 17-gauge.

My dad has 17-gauge caterpillar tunnels on his farm, and some of those have bent in the wind. If he were replacing them today, he'd go with 14-gauge across the board. We learned the same lesson at Farmers Friend — in our early days, we sold 17-gauge gothic structures to keep prices low, but we started seeing storm damage that we weren't comfortable with. It's devastating for a grower to lose a tunnel. So we redesigned our kits to include 14-gauge steel as the standard on almost everything.

A high tunnel is not the place to save money on materials. A few thousand dollars in savings on a cheaper structure means nothing if the tunnel comes down and takes your crop with it.

What About Bow Spacing and Trusses?

Bow spacing depends on your climate. If you get significant snow loads, go with 4-foot spacing between bows for maximum strength. In milder climates — like ours here in zone 7 — 5 or 6-foot spacing has worked fine.

Trusses are the horizontal braces that connect the two sides of each bow. For wider tunnels (30 feet and up), trusses on every bow are important for structural integrity.

My dad has a hard-won lesson here. He lost two tunnels to an ice storm, and he believes the failure was an engineering issue — the trusses were positioned too high on the bows, and the structure bent right at the edge of the truss. It was a shock. He didn't think the ice load was enough to cause problems, but losing two tunnels at once made it clear that truss design and placement matter.

Why Should I Choose All-Metal Construction?

My dad is emphatic about this one: go all-steel.

In the early years at Bountiful Blessings Farm, they used wood for sidewalls and end walls. The problem? Moisture constantly drips off the roof of the tunnel and runs down the sidewalls. They deliberately avoided treated lumber because they didn't want chemicals near the soil. The untreated wood lasted maybe two or three years before it needed to be replaced. It was a constant maintenance headache.

Wood on end walls is less of an issue since they don't get the same moisture exposure. But for baseboards and sidewalls, metal is the only material that makes sense long-term. It's one less thing to worry about on a farm where the to-do list is already endless.

What Size High Tunnel Should I Start With?

My dad's advice is straightforward: the biggest you can afford, without compromising on quality.

It's tempting to stretch your budget by buying the largest tunnel available at the lowest price. But those cheap, oversized tunnels often lack the structural integrity to last. My dad has watched friends lose tunnels that simply weren't built to handle real weather — including a friend in Indiana who lost two cheap tunnels just last winter.

A smaller, well-built tunnel will serve you far longer than a large, flimsy one. Buy quality first, then scale up as your farm grows.

What Else Should I Look For in a High Tunnel Kit?

Beyond the structure itself, there are a few things worth evaluating before you buy:

What's actually included in the kit? A lot of greenhouse companies advertise a compelling price, but when you dig in, the kit doesn't include basics like roll-up sides, end walls, or hardware. You end up paying significantly more in add-ons just to get a functional structure. Look for kits where everything you need is in the box.

Wind bracing. Corner wind bracing is essential. One of my dad's early tunnels didn't have it, and it was a problem. Make sure bracing is included or available as part of the kit.

Purlin count. More purlins (the horizontal bars running the length of the tunnel) generally means a sturdier structure. It's a good indicator of overall build quality.

Installation instructions and support. This is one that gets overlooked, but it matters — especially for your first tunnel. Most high tunnels are not a beginner DIY project. You're going to get a big pile of metal, and without clear instructions, it can be overwhelming. Look for companies that provide detailed print manuals, video walkthroughs, and responsive customer support. Once you've built a few tunnels they're all fairly similar, but for that first one or two, good documentation makes the difference between a weekend project and a week-long headache.

Frequently Asked Questions

A Gothic peak with straight sidewalls at least 6 feet high is ideal for most market farmers. The Gothic shape sheds snow and ice far better than a Quonset arch, and straight sidewalls give you full usable growing space along the edges of the tunnel. Avoid the Quonset shape for high tunnels — it's fine for caterpillar tunnels but wastes space in a walk-in structure.

Look for 14-gauge steel bows at minimum. Steel gauge works inversely — the lower the number, the thicker and stronger the metal. 14-gauge bows are nearly double the strength of 17-gauge, and the cost difference is small compared to the risk of losing a tunnel in a storm.

In areas with heavy snow loads, 4-foot bow spacing provides maximum strength. In milder climates like zone 7, 5 or 6-foot spacing is adequate. If you're unsure, closer spacing is always the safer choice.

All-metal construction is strongly recommended. Wood sidewalls — especially untreated lumber — deteriorate quickly from the constant moisture that drips off the tunnel roof. Untreated wood may only last two to three years before needing replacement. Metal baseboards and sidewalls eliminate this maintenance issue entirely.

The biggest you can afford without sacrificing build quality. A smaller, well-built tunnel will outperform and outlast a larger, cheaply made one. Losing a tunnel to a storm costs far more than the price difference between a budget kit and a quality structure.

Look for kits that include everything needed for a functional structure: bows, purlins, baseboards, roll-up sides, end walls, hardware, and wind bracing. Many companies advertise low base prices but charge extra for essential components. Also evaluate the quality of installation instructions — detailed print manuals and video guides make a significant difference, especially for first-time builders.

A well-built high tunnel can last 25 years or more. The oldest tunnel at Bountiful Blessings Farm has been in continuous use for 25 years. Longevity depends on steel quality, proper construction, and replacing the greenhouse plastic as needed (typically every 4–6 years depending on the plastic).

The Takeaway

A high tunnel is a long-term investment in your farm's productivity and resilience. The tunnel my dad is standing in during our conversation is 25 years old — that's the kind of lifespan you can expect when you buy quality.

Prioritize shape (Gothic or straight sidewall), steel thickness (14-gauge minimum), all-metal construction, and trusses on wider tunnels. Buy the biggest you can afford without cutting corners on structure. And take the time to evaluate what's actually included in the kit before you compare prices.

Your tunnel should be the one thing on your farm you don't have to worry about when the wind picks up.

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