Growing Corn in a High Tunnel
Downsizing the garden has given me some wiggle room for experimenting. When you grow and do the same things year after year gardening gets monotonous. Without the need for thousands of plants and lots of variety now that I’m not market gardening I find new ways to get creative. Growing corn in a high tunnel was one of this year’s experiments.
The experiment was a success so we’ll be growing corn in a high tunnel next year. There aren’t many differences in methods between the tunnel and outdoors.
How to Grow Corn in a High Tunnel
Amend the soil as needed. If you haven’t done a soil test in a while now’s a good time. We add lime in the fall because it takes time to work. Corn is a heavy feeder so add plenty of nitrogen but not so much it burns the roots. I dug holes 12″ to 18″ deep and filled them with water twice to soak the soil. High tunnels aren’t open to rain.
Corn germinates best in soil 60° or warmer. If you want to add additional warmth and control weeds you can lay out IRT and cut holes. I didn’t because there isn’t a week problem on that side of the tunnel.
After the water drained I added fish guts to the bottom, and mixed compost into the soil, and then filled in the holes.
I used circles because I wasn’t planting a lot of corn. If you plant rows they should be at least four feet long and there should be a minimum of four rows for good pollination. Planting in small circles helped pollination. In a 12″ to 15″ circle I planted seven or eight seeds.
The soil stays warmer at night in the tunnel than it does outside so germination was fast, four or five days. Keep the soil moist by watering heavily once or twice a week. The number of times you’ll need to water depends on how much organic matter is in the soil to hold water, the temperature, size of plants and wind. Roots will grow deep to get to the rotted fish and you’ll notice a growth spurt.
Continue to give the plants nitrogen through the growing season. When we kept fish we caught I dug a hole beside the roots, dumped the guts in, watered well and refilled the hole. There was never a fish smell to attract raccoons and skunks. Use whatever you normally use for a nitrogen fertilizer.
Every silk on an ear of corn is attached to a potential kernel. The silk must be pollinated for the kernel to grow. The plants closest to the door were pollinated best because the wind blew the plants more than those in the back. The sides were rolled up all summer but that doesn’t provide enough air flow high to move the plants for successful pollination. There were a few ears that weren’t edible and a few that should have been better pollinated. Next year I’ll plant the corn in the front half of the tunnel and give the end plants a better shake to improve pollination.
The variety I chose averages six feet tall. Growing corn in a high tunnel gives extra warmth and allows for the easy addition of nitrogen. This corn averaged seven feet and topped out just over ten feet. The stalks are thick and heavy and supported the extra height well.
There were no pests! It’s nice to peel back the shucks and not find corn earworms.
Clean up was easy. I used long-handled pruning shears to cut the stalks at ground level. Leaving them higher than ground level is potential to trip over the stubs. The roots will start to break down and feed the soil so continue to water if you’re not going to plant something in that spot for winter crops. Growing corn in a high tunnel was a great experiment that results in delicious sweet corn.