Our 3 high tunnels and 1 greenhouse.
High tunnels are a great way to extend your seasons. They are much more comfortable than the low tunnels because you can stand and walk comfortably and raise a lot of food.
What is a greenhouse? A greenhouse is basically a heated high tunnel-that’s it. It will require electricity, vents, fans and heat. They are great for raising heat loving produce such as tomatoes, cukes, peppers and eggplant.
Our greenhouse allows us to have early tomatoes, peppers and eggplant.
The best high tunnel design is the gothic design as in the picture below. This is especially necessary if the width of your house is over 24′. It is more stable and will shed snow whereas the quonset design will not. The gothic are more stable and will not collapse under the weight of snow. If you get an abundance of snow, you will still have to clean the snow off the roof right away, but it will hold up until you do.
Our high tunnels also allow us to have early baby lettuce, head lettuce, carrots, spinach, beets, kale, cilantro, basil, arugula and radishes. In the picture below you can see rainbow and sugar snax carrots. The carrots were planted in January and will be ready in late April. On the sides we have green star leaf lettuce and red romaine head lettuce. When the temperature drops in the teens at night , we cover the plant using row cover(see picture) and low tunnel hoops. Also notice in the picture below, that the sides are rolled up on this house. This is really important when the sun is shining even in the winter and definitely with summer temps .
You also will need a shade cloth. This can drop the temperatures 15 degrees in the summer.
Shade Cloth on High Tunnel.
You might wonder why we would have food in a tunnel during the summer. We have found that raising tomatoes, cukes , eggplants, and peppers in the tunnels( along with nutrient dense minerals fed to the plants), reduces blight, fungus and disease. We live in the south, and blights and fungus are a constant battle when these are raised outside.
You don’t want to skimp on your plastic. The 6 ml greenhouse plastic will last at least 5 good years. You also want the clear not the opaque plastic.
These tunnels also allow you to have garden goods far into the winter. With additional coverings inside you can extend lettuces, onions, cabbage, radishes, beets and greens and more far into the winter.
It is an investment, but if you are a serious gardener, it is well worth the expense. Craigslist and other internet trade sites can be a great source to find used greenhouses. There are also greenhouse companies. Shop around.
For DIYers, you can invest in a hoop bender from Johnnys Select Seeds. This will bend chain link fence rails and give you about a 14″ wide tunnel and any length that you want. They need to be laid out on 4′ increments and fit the hoops into pipes in the ground, (see below). The length of the pipes will determine the height of your walls. Some people use pvc pipe. We would recommend the steel because it would be sturdier and last longer.