High Tunnel Production

What is a high tunnel, and how does it differ from a greenhouse?

A high tunnel is usually a simple hoop structure covered with plastic, with crops grown in the ground and often with no permanent heating. A greenhouse is generally more enclosed and may have active heating and controlled systems. Neighbors and extension staff can tell you how local tunnels performed in last winter's storms, which is practical information you cannot get from a catalog.

Because it is unheated, a tunnel mainly extends the season at both ends and shelters crops from rain, wind and some cold. It does not make winter into summer. Set expectations according to your climate.

Many farms find that a tunnel pays off most when it protects a few high-value crops, rather than trying to grow everything under plastic. Think about which crops in your market suffer most from rain, cold nights or early frost.

• Unheated, soil-grown, plastic-covered
• Season extender, not a winter summer

What site and soil are right?

Choose a level, well-drained site with good sun and access to water. Wind exposure and snow load matter, so ask the maker about ratings and ask local growers what has survived your weather.

Soil in a tunnel is under cover, so rain does not leach it or rinse salts out. Test regularly, and ask your extension office how to manage salt buildup and fertility over time.

• Level, drained ground with sun
• Water within reach
• Plan for wind and snow

Which crops do well?

Tomatoes, peppers, cucumbers, leafy greens and many other vegetables are common tunnel crops, along with some flowers and berries. Rain protection can reduce certain leaf diseases, while heat can create other problems.

Choose crops that your market wants and that your tunnel can protect. Ask local growers and extension staff for variety recommendations and planting windows in your region.

Rotation is harder under cover, so plan beds and crop families ahead of time. Growing the same crop in the same soil year after year can build up disease, and you cannot rely on rain or winter freeze to reset the soil.

• Pick crops your market wants
• Rotate crop families where possible

How do you manage heat and ventilation?

Tunnels can overheat quickly on sunny days, even in cool seasons. Roll-up sides, end vents and shade cloth let you control temperature, and someone has to open and close them. Missing a hot afternoon can cook a crop.

Plan how you will manage vents when you are away. Automatic openers exist, but they need setup and checking. A neglected tunnel can lose a crop in a single day.

Wind is the greatest threat to many tunnels. Strong gusts can lift plastic and damage the frame if ends are left open or the cover is loose. Learn how to secure plastic and when to close up.

What about water, pests and disease?

Rain does not reach the plants, so irrigation is entirely on you. Drip lines are common because they keep leaves dry and use water efficiently. Check lines often for clogs and leaks.

Warm, protected air suits some pests and diseases. Scout frequently, rotate crops where you can, and keep the structure clean. Follow pesticide labels and state rules if you use any.

• Use drip irrigation where possible
• Scout often under the plastic
• Rotate or manage soil to limit disease

Are there programs that can help with costs?

Some conservation programs have offered help with high tunnel systems for eligible producers. Availability, rules, and funding differ by state and change over time, so contact your NRCS service center or look at Farmers.gov to see what is open now.

Do not buy or build with the expectation of reimbursement until you understand the program's rules, since starting before approval can affect eligibility. Keep copies of any application paperwork and receipts in case you are asked for documentation.

How should you get started?

Begin with one tunnel and one or two crops. Keep a log of temperatures, planting dates, losses and sales. Learn how the structure behaves in your weather before you add more.

Maintenance is part of the job. Check plastic for tears, secure ends before storms, and clear snow according to the manufacturer's guidance. Visit nearby farms with tunnels to see what works.

Keep manufacturer's instructions and local weather records in one folder. If damage occurs, you will want that information handy for repair decisions and for any insurance conversation.

Last reviewed: November 12, 2026. Written by the Rural Farm Life Editorial Team. See our editorial policy.