LANCASTER, Pa. — There’s a lot to consider when it comes to selecting the right high tunnel.
From location to design and the amount of money it takes to put one in, it’s a lot to think about.
But the payoff can be well worth it.
“Everybody is in this room for one reason and one reason only — locally grown,” Steve Bogash, regional horticulture educator from Penn State, said to a group of 50 people attending a high tunnel school at the Lancaster Farm and Home Center, March 14 and 15.
“Our season is too short to satisfy our client’s needs. That’s the reason we do high tunnels,” Bogash said.
It’s a lot more complicated than just putting up tunnels and hoping for the best, though.
Bogash said a lot of factors have to be taken into consideration, including placing a tunnel at the right angle to take advantage of prevailing winds, making sure there is good enough soil and drainage inside the tunnel, and putting it in an area where the sun can get in.
Depending on how early or late you plan on growing crops inside a high tunnel, a supplemental heating system, either propane or heating oil, might be necessary.
“If you’re going to go early, you probably need to be thinking about supplemental heat,” he said.
When it comes to tunnel placement, growers should allow enough room — 10 to 12 feet between each tunnel — to allow for snow to roll off the top in the winter and to allow trucks to come in fairly easily for pick up and drop off, Bogash said.
Plants need sun and Bogash said putting a tunnel where there is consistent sunlight is crucial to getting good, consistent crops.
“If you are shaded for even part of the day, that’s not the place to put a tunnel,” he said.
One of the most popular crops to grow under a high tunnel is tomatoes.
Tom Ford, commercial horticulture educator with Penn State, compared growing tomatoes in either a soil-less system or in the ground.
To grow tomatoes in a soil-less system involves growing them in a bag or even hydroponically, which shows their relative flexibility.
Bags are usually pathogen-free, meaning you don’t have to fumigate the soils to ensure the tomatoes grow properly. Ford said the bags are also relatively easy to use and in some cases can be reused.
But these systems can be expensive — between $2 and $2.50 for the bag itself.
“You’ve got the investment in the bags. You’ve got the investment in the potting material. It can add up quickly,” Ford said.
Learning the system can also take a while for some growers, and there is also the customer perception of growing tomatoes in a bag, which might be a turnoff to some.
Growing tomatoes in the ground has its advantages and disadvantages too. It’s cheaper to do, there is less of a learning curve, less water is needed, and it is perceived as sustainable.
The disadvantages are many, though. Growing tomatoes in the ground means you can’t easily relocate the high tunnel. Crop rotation is also required to prevent pathogens. And there are more pests and diseases, in general, to worry about when tomatoes are grown in the ground.
Ford said it’s not a question of which system is better, but which system works for a particular grower in a particular situation.
The high tunnel school in Lancaster was one of several held throughout the state this month.
Bogash said another factor that growers should remember is to check with the local municipality to see if it has anything on the books covering high tunnels and greenhouses for taxing purposes.
He said in some cases, growers have been slammed with high building permit fees and other taxes if the municipality considers the high tunnel a greenhouse, especially when many improvements have been made.
“Find out what your municipality requires. Make sure they understand. What they usually want is their building fee,” he said.