High tunnels, plastic-covered structures in which plants are grown, can extend the growing season of flowers, fruits and vegetables.
As the sunlight bounces off the soil, the wave lengths get longer — but they can’t escape the plastic easily. This causes heat to build up, making the air, soil and plants in the high tunnel warmer.
“A key point of any high tunnel is to have ventilation,” said Liz Maynard, Extension specialist at Purdue University. “A very common way to ventilate is to have roll-up sides. It’s the only way of keeping it from getting too hot in the spring or summer.”
Maynard shared some of the pros and cons of using high tunnels:
Pros:
- Plant crops earlier
- Harvest crops later
- Improve fruit quality
- Opportunity to grow new crops
- Less rain damage
- Higher yields
- Possible disorders due to higher temperatures
- Fewer pesticides are permitted
- May need to hand pollinate or bring in pollinators
- Can be costly
- Subject to wind, snow and rain damage
- Involves more manual labor