A high tunnel is an unheated, plastic covered structure used to grow and protects plants. They are vented naturally and there is no "pumped-in" heat; they allow for passive heat from the sun. On a sunny cool spring day, the temperature can easily climb to over 100 degrees inside when the outside temperature is only 40-50 degrees. Unlike most greenhouses, high tunnels have no floor and the crops inside are grown in the ground.
Why use a high tunnel? When you use a high tunnel you can easily extend your season over a month on each end. You can plant crops sooner and harvest them later in the year. Using other products such as row cover, you can grow cold tolerant vegetables year around.
Last year was our first year to experiment with year-round growing. This idea is tricky, considering how varied and extreme Kansas weather can get. Despite the weather, we successfully grew spinach and had fresh spinach salad almost every week all winter long.
It is said for every layer of plastic or row cover you put over a crop, it's like moving 500 miles south. While you can't grow warm season crops, like tomatoes, peppers, cucumber or watermelon all winter long, you can grow cool season crops, like leafy greens, cole crops (broccoli is really good), and root vegetables. While during the winter the crops don't grow alot, they are more in a state of living cold storage. Yes, the spinach and lettuce will freeze, but when the sun comes out they will warm up and thaw out.
To learn more about high tunnels check out this link.
I started with 2 high tunnels 3 years ago. They were very small 12 by 18 and 8 by 12. However, even with those small tunnels I saw the benefit and I had to get more. All steel high tunnel kits are expensive and we don't have that kind of money to spend. So, I did the next best thing. I created my own design and started to build my own, at a fraction of the cost.
Today we have 6 high tunnels in production, 4 stationary tunnels and 2 movable ones. The movable tunnels are a new idea and new this year. They are steel-framed, my own design, and my father-in-law helped bend the pipe. The advantage of a movable tunnel is you can use the same structure to cover more than one crop. For example, I currently have the two building protecting broccoli and potatoes. In several weeks, we will be moving the buildings to a new growing area. The buildings will slide down on wooden rails. In this new position, they will protect and cover cucumber and squash. The broccoli and potatoes will live and grow outside. Once those crops are done, I will prepare the soil for a fall planted crop. This crop will be planted outside and when the days start getting cold, and the squash and cucumber season is over, we will move the building back over the new crop and harvest it into the winter. These two 16 feet by 32 feet buildings will cover over 3,000 square feet over the growing season.
Meet the high tunnels:
Old Reliable, this was my first tunnel I build. It is still in use. It is showing its age, but I think we can get another year out of it.
Here are my two tunnels from last year.
Here is my new big tunnel for this year. It is covered and has tomatoes planted inside. I need to take a new picture.
Finally, here are my new Movable tunnels.
As the year goes along, we will be posting new pictures of the tunnels and images of the crops growing inside.