Greenhouse Kits - build a high tunnel
So, you're interested in one of those greenhouse kits? There are many to choose from, so grab a cup of coffee and start browsing through the catalogs. Better still, stay right here and take a look at a high tunnel and see if that might be right for you.
A high tunnel is really a great big greenhouse in a hoop house design, without all the fans and vents and whatnot. It gives you plenty of room to grow what you'd like in support of a plan for frugal living that includes eliminating the produce bill.
With a large kit, you'll have room left over for a patio and chairs to relax inside and enjoy your beautiful garden.
Here are Catherine and Martin Wissner. They live just outside of Cheyenne and they own both a low tunnel and a high tunnel. Out here in the Wyoming we have drying winds and damaging hail, so having your veggies under cover is a good idea. You'd be surprised at how drying winds stunt the growth of just about everything.
The high tunnel over at the Wissner spread is 26 by 48 and it is 13 high in the center.
That's plenty of growing space and plenty of head room. It's large enough to park 9 cars inside. You get the idea - it's plenty big.
But don't park cars in there. It's much too valuable for that. Grow fruits and vegetables instead. It's more fun, a great money saver, and tasty as well.
Of the greenhouse kits on the market, this high tunnel is made from 14 gauge steel tubing that form "ribs" spaced 6 feet apart. Each of the ribs is made of 5 curved steel tubes that fit together and are fastened to one another with heavy duty sheet metal screws.
The ribs are secured to the ground with ground stakes that are simply metal tubes pounded into the ground. The ground stakes are made from the same material and accept each end of the "ribs" for a secure fit. Heavy turnbuckles hold the corners and most other "ribs" tight to the ground.
Six purlins hold the "ribs" together; three on each side, with no ridge piece running down the center of the arch. The upper two purlins are held to the "ribs" by special clamps, shown lower right. The lower purlins are fastened to the "ribs" with bolts.
The lower purlins are made of wooden 2 by 4s and serve as an anchor point for the poly covering that is stretched over the top. Both the poly on the sides and ends is held in place with "wiggle wire". Using this approach allows the plastic covering to be attached quickly and securely without putting holes in it.
The "ribs" are also tied together with wooden "high sides" at the bottom of the structure. The "high sides" are also where earth anchors and turnbuckles can be used to pull the structure down and hold it in place. This is important because high winds could lift, move or tip the structure if it isn't secured to the ground.
It wouldn't be a good feeling knowing that you purchased one of the greenhouse kits and then had the wind destroy your investment. Out here where the wind blows strongly, it pays to be very careful with securing the structure to the ground.
The earth anchors for this structure are about 3 feet long and were installed using a heavy drill with a homemade adapter. Try installing one by hand and you'll be getting out your largest drill and figuring out a way to make it drive the earth anchors for you.
Greenhouse kits offer various options for finishing the ends of the structure. This structure originally had plastic ends that were hard to secure in the wind, so wooden ends were constructed for added support. A pedestrian door was also incorporated into the wooden framing at one corner of the high tunnel.
As you can see in the picture below, this spacious high tunnel allows for full panels of livestock fencing to be brought in and set up as arches on which to grow melons and such. I know plenty of people that don't have an outside garden so spacious. What a great place to raise vegetables.
And, I should mention that the Wissners grow all their own produce and keep themselves supplied year round with fresh, canned, frozen and dried goodies from the garden. That's a good way to be. They always know what is in and on their food.
This high tunnel has roll up sides that work with a mechanism operated by hand. It is amazing to see that the 48 foot long poly covering rolls up with ease with just a modest effort. The portion of the sides that roll up are held in place by a "net" of nylon rope so as not to blow around in high winds.
This structure has no automatic vents or fans, so all ventilation is done with the roll up sides. The higher you roll them, the greater the ventilation effect.
Ventilating manually like this is one way to save on electricity that would otherwise be spent trying to exhaust hot air from the structure during the intense sun of the summer.
One item missing from this and most other similar greenhouse kits is cross bracing to prevent the structure from collapsing from one end to the other. A combination of the ground stakes and the "rib" to purlin clamps provide sufficient support to prevent this from happening.
Also, diagonal bracing is not typically included in greenhouse kits such as this. The rigid steel tubes used to create the "ribs" obviates use of diagonal bracing. In areas of heavy snow, I would suggest diagonal bracing or installation of other supports to hold deep wet snow that might accumulate on the top of the hoop house structure.
As you can well imagine, assembling large greenhouse kits like this high tunnel requires helping hands - lots of them. Get a few helpers before you begin a project like this. It most certainly isn't something for one person to do.
Well, there you have it, a spacious high tunnel assembled from one of the greenhouse kits. It provides lots of space, great results, and is well worth the time and effort to assemble. If you're looking for a large hoop house, you might take a look at the greenhouse kits on the market for creating a high tunnel like the Wissners have just outside of Cheyenne.
There is no doubt in my mind that a high tunnel of this size will provide nearly all of the produce that a small family focused on frugal living will ever need. Happy vegetable gardening.
Done with Greenhouse Kits, take me back to Build Your Own Greenhouse