Multi-Tunnel Greenhouses
TunnelPro Plus
Harnois Greenhouses offers high polytunnel greenhouse systems designed for open-field growers. Whether you’re cultivating small fruits, leafy greens, or vegetables in open fields, our multi-tunnel greenhouses provide optimal crop protection, superior light diffusion, and reliable weather resistance.
The TunnelPro Plus is a multi high tunnel greenhouses available in a single width of 31′ 6”. Each arch is made with exclusive oval tube 2″ × 3 9/16″ using structural steel and high levels of galvanization (galvalume). This combinaison makes Harnois’ arches one of the strongest on the greenhouse market and one of the longest lasting against corrosion.
It’s easy to assemble with concrete-free anchors, wide arch spacing, and twinning options—with or without structural gutters—for enhanced stability.
Its height (up to 18’ ) allow easy equipment access and maximize growing space. Compliant with the International Building Code (Canada & USA), it’s built to withstand high wind loads. With excellent value and a typical ROI in just three years, TunnelPro Plus is a smart long-term investment to protect fragile crops such as strawberries and raspberries.
31' 6'' multi-tunnel greenhouses
- Width: 31' 6'', with adjustable length to suit your needs
- Arch in 2" × 3 9/16" galvalume oval steel tube
- Anchorages with 3″ round posts in screw model
- Cold frame: 3-seasons
- Minimum configuration: 3 tunnels
- Quality and processes ISO 9001-2015
- Hardware: Galvanized Nuts & Bolts
- Spring-loaded polylocks with pins and hardware
- Roll of 6mil polyethylene
Key Benefits
- Extended growing season
- Better yield : Higher crop density
- Better product quality and predictability
- Harvesting speed up to 40% faster
- Full access is available for tractors and workers.
- Lower operating costs (labor and machinery)
- Reduced use of phytosanitary products
- Reduced water consumption and fertilizer losses
Case Study:
Transitioning from Open-Field to High-Tunnel Production, Innovative
Strategies for Small Fruit Growers
Switching from open-field to high-tunnel production transformed our operation. With 15 hectares of TunnelPro Plus structures, we’ve gained better crop quality, extended our season, and reduced our operating costs by 50% compared to open-field. It’s a game-changer for small fruit production.
TunnelPro Plus - Greenhouse Size

Options
- Suncooler film
- Structural Rain Gutter
- Elevated Bench
- Fertigation system
- Full-width roll-up doors - Opening up to 13'
- Full-width roll-up doors - manual and motorized options
- Side Roll-Up Ventilation
Made in Canada, shipped worldwide.
Local installation across Canada, USA, and Mexico.
About the TunnelPro Plus
The TunnelPro Plus is an exceptional choice for growers seeking a 3-season high polytunnel greenhouse that combines durability, efficiency, and adaptability. This economical polytunnel is designed to optimize crop production while providing a cost-effective and reliable solution for diverse growing needs.
The TunnelPro Plus stands out with its robust frame (made in Canada), crafted from high-grade galvanized steel, ensuring exceptional strength and longevity. Its oval design minimizes stress on polyethylene films, extending their lifespan and reducing maintenance requirements.
Quick and easy to assemble, these high polytunnels are ideal for growing soft fruit, for open-field growers wishing to convert to controlled-environment agriculture.
From climate to crop sensitivity to market demands, we understand the complexities faced by production managers. High Polytunnels are a cost-effective solution offering unique advantages to growers.
Rise of the High Polytunnel Greenhouse in North America

The rise of high polytunnel greenhouses is transforming soft fruit production across North America, offering growers a reliable and cost-effective solution to extend the harvest window and improve crop quality. This innovative structure, now proudly available as the first Canadian-made model by Harnois, provides optimal climate control and protection from harsh weather, making it ideal for delicate crops like strawberries and raspberries. Producers such as Polyculture Plante and Entreprises Pitre are leading the way with successful installations, proving the model’s value in Quebec’s diverse climate. With increased consumer demand for locally grown berries and the need for sustainable farming methods, high polytunnel greenhouses are quickly becoming a key asset in the future of North American berry production.
They also allow earlier planting, reduce disease pressure from rain, and improve labour efficiency—giving growers a competitive edge in both yield and quality. Combined with integrated irrigation and fertigation systems, these structures support higher-density planting and consistent production from spring to fall.
Contact your local agent
Start your operation or expand with ease using a high polytunnel greenhouse —contact us or request a quote today!