High Tunnel Greenhouse Growing

I have always had a small greenhouse where I’ve been able to grow tomatoes for snacking in the summer, but a few years ago, we purchased a 21×60 high tunnel greenhouse, and it was a game-changer. I have grown enough tomatoes to can hundreds of jars and enough peppers to freeze enough for a year.

High Tunnels can be a significant investment, but in my opinion, a worthwhile one if your goal is to extend your growing season and to grow lots of gorgeous food!

Growing produce in a high tunnel is a different experience from growing outdoors and requires some extra effort, but it’s well worth it.

The first thing to consider is the location of your greenhouse. We faced ours with the doors on the north and south ends with the broadsides facing east and west. Situating it this way allowed our prevailing winds, which blow from the south, to blow through the tunnel doors. This has helped to keep the tunnel much cooler on hot days.

Greenhouses can overheat very quickly, even on overcast days, so roll-up sides are a worthwhile investment. Our tunnel sides roll up 3 feet with is adequate. You can also add fans to help move the air through your greenhouse, and it can be set to turn on when the temperature gets too high.

In most outdoor gardens, it is a good practice to rotate your crops; In a greenhouse, this is usually not possible due to the small space, so amending your soil and fertilizing your plants is essential. 

Before having the high tunnel, I used manure compost in my garden with great success, but the high tunnel required extra amending. I top-dress the beds with compost in the fall and again in the spring. I also mix in trace mineral Azomite, Gypsum, and good 4-4-4 organic fertilizer.

Once the plants begin to flower, I add bone meal to the base of the plants. Watering the greenhouse can be time-consuming. I have to water mine by hand because we have silty water that plugs up any drip irrigation, but drip irrigation is a good option if you have clean water. I water my high tunnel based on the needs of the plants and the temperature. In general, plants require a deep watering of at least an inch once a week, more if it’s hot. I find twice a week is best during the summer.

If you love to grow food and live in the North give greenhouse growing a try – you won’t regret it!

Happy Growing!