Commercial Greenhouse Solutions for Every Industry
Harnois Greenhouses is a Canadian manufacturer of high-performance commercial greenhouse structures, proudly serving growers and operations across North America since the 1960s. As a division of Industries Harnois Inc., we engineer, manufacture, and install greenhouses tailored to the specific needs of each agricultural and horticultural industry we serve, from large-scale produce operations to institutional research facilities.
Whether you are a produce grower seeking year-round yields, a garden center looking to enhance the retail experience, or a research institution requiring a precisely controlled environment, Harnois delivers greenhouse structures built to perform in demanding North American climates.
Greenhouse Industries We Serve
No two growing operations are the same. That is why Harnois designs its commercial greenhouse structures around the unique requirements of each industry, crop type, climate zone, production volume, and operational goals. Below is an overview of the six main greenhouse industries we support across Canada and the United States.
Produce Greenhouses — Fruits & Vegetables
The produce greenhouse industry is one of the most demanding and fastest-growing sectors in controlled environment agriculture. Growers need structures that deliver reliable snow-load performance, optimal light transmission, and stable year-round climate control to maintain consistent, high-quality harvests regardless of the season.
Harnois commercial greenhouses are used by produce growers to cultivate tomatoes (cluster, grape, and cherry varieties), peppers, cucumbers, leafy greens, lettuce, and spinach. Our structures support both heated four-season production and extended-season growing, giving produce operations the predictability needed to compete in today’s market.
By controlling temperature, humidity, and light inside the greenhouse, growers in the produce industry can schedule harvests, reduce crop losses from weather events, and deliver consistently premium-quality product to their buyers.
Floriculture Greenhouses — Flowers & Ornamentals
The floriculture and ornamental greenhouse industry depends on structures that offer superior light diffusion and stable climate conditions for growing high-value crops. Harnois greenhouses provide the optimal environment for bedding plants, hanging baskets, potted perennials, seasonal flowers, and specialty ornamentals.
Our structures are used by both high-volume commercial flower producers and local garden centers seeking to offer a consistent, protected growing and retail space. Reinforced overhead support options are available for operations growing heavy hanging basket crops, one of the most weight-intensive product categories in the greenhouse industry.
Nursery & Tree Seedling Greenhouses
Propagation and nursery operations require environmental stability, precise temperature control at the root zone, and efficient use of floor space. Harnois greenhouse structures provide the modularity and climate management essential for growing vegetable transplants, tree seedlings, herb starts, and grafted plants at commercial scale.
Misting systems, ventilation options, and heated benching configurations can all be integrated into nursery greenhouse designs to maximize plant health, reduce transplant shock, and improve rooting consistency. This greenhouse industry segment is particularly active in reforestation, forestry, and large-scale vegetable transplant supply chains across Canada.
Soft Fruit Greenhouses — Berries & Strawberries
High tunnels and commercial greenhouses have transformed the soft fruit industry by extending growing seasons, protecting crops from weather damage, and delivering higher-quality berries to market. Harnois structures are used by soft fruit growers to produce strawberries on soil or substrate systems, raspberries, blackberries, and blueberries under cover.
In many growing regions, protected cultivation of soft fruits extends production by two to three months compared to open-field growing, a significant competitive advantage for operations selling through retail, farmers’ markets, or direct-to-consumer channels. Our structures are optimized to provide the light diffusion and ventilation that berry crops demand for consistent fruit set and color.
Garden Center Greenhouses
Garden centers operate at the intersection of the greenhouse industry and retail, requiring structures that protect plant inventory while creating a welcoming shopping environment for customers. Harnois commercial greenhouses offer superior light transmission, customizable ventilation, and reliable structural performance through every season.
Our structures are ideal for displaying bedding plants, annuals, perennials, hanging baskets, and seasonal décor. Whether you operate a large-format garden center or a local nursery with retail ambitions, a Harnois greenhouse helps you maintain plant quality, extend your selling season, and build a space that converts shoppers into loyal customers.
Institutional & Research Greenhouses
The institutional sector is one of the most specialized segments of the greenhouse industry. Schools, universities, botanical gardens, public institutions, and research centers require greenhouse structures that support precision-controlled experiments, educational programming, and long-term botanical collections.
Harnois builds institutional greenhouses ranging from simple high tunnels used in school gardens to advanced glass structures equipped with automated climate systems for university research programs. Our engineering team works directly with institutional clients to design structures that meet both the technical requirements of the research and the budget realities of public or academic funding.
Harnois Greenhouses is a division of Industries Harnois and a Canadian manufacturer of high-performance commercial greenhouse structures. We design and install engineered greenhouses for growers and garden centres across Canada and the United States, built to deliver reliable snow-load capacity, optimal light transmission, and stable year-round climate control.
We support a wide range of agricultural and commercial sectors, including:
Fruits & vegetables
Nurseries & tree seedlings
Soft fruits
Institutional & research facilities
Garden centers
Our structures are developed to help producers operate efficiently, protect crops in demanding climates, and achieve consistent, high-quality results season after season.
Commercial greenhouses enable growers to offer produce earlier and later in the season, maintain constant yields, and consistently produce high-quality crops, especially for climate-sensitive varieties. Common fruits and vegetables grown in Harnois greenhouses include:
- Tomatoes (cluster, grape, cherry)
- Peppers (sweet, hot)
- Cucumbers, lettuce, spinach, and leafy greens
By controlling light, humidity, and temperature, growers can achieve year-round production or early-season harvests, depending on the crop and setup.
Harnois greenhouses are ideal for garden centers,retail areas, flower growers, and landscapers. Our structures provide optimal light diffusion and climate control for:
- Bedding plants (petunias, impatiens, begonias)
- Hanging baskets and potted plants (reinforced greenhouse required)
- Perennials and seasonal flowers
We support both high-volume commercial operations and local garden centers seeking to offer a better shopping experience, stable climate, and high-quality products.
If you produce seedlings, cuttings, or young plants for transplant, propagation greenhouses are essential. Harnois greenhouses offer the environmental stability and modularity required for:
- Vegetable transplants
- Tree nurseries
- Herb seedlings
- Grafted plants
Controlled root zone temperatures, optimal ventilation, and misting options are available to maximize plant health and minimize transplant shock.
Harnois commercial greenhouses and high tunnels provide the ideal controlled environment for soft-fruit producers seeking longer seasons, higher yields, and premium-quality berries. Our structures deliver optimal light diffusion, ventilation, and climate stability to support near year-round production in many climates.
Perfect for:
Strawberries (soil or substrate systems)
Raspberries and blackberries
Blueberries and specialty berries
Whether supporting high-volume berry operations or smaller farms looking to extend their season, Harnois high tunnels offer reliable protection, reduced weather-related losses, and consistently high-quality fruit.
Harnois commercial greenhouses provide garden centers with bright, welcoming, and climate-stable retail environments that enhance the shopping experience and protect plants throughout the season. Our structures offer superior light diffusion, customizable ventilation, and reliable snow-load performance, ensuring your inventory stays healthy and visually appealing, even during weather extremes.
Ideal for:
Bedding plants, annuals, and perennials
Hanging baskets and potted plants (reinforced structures available)
Seasonal displays and outdoor retail expansions
Whether you operate a large-scale garden center or a local nursery, Harnois greenhouses help you maintain a consistent climate, improve plant quality, and create an inviting retail space that encourages customer engagement and boosts sales. Our flexible designs adapt to your layout, merchandising needs, and growth plans.
Institutional and research greenhouses
Harnois also supports schools, community projects, and institutional researchers who want to integrate greenhouse production into educational, social or research environments. These institutional greenhouses are tailored for:
- High & Elementary Schools
- Public & Botanical Gardens
- Conservatories
- Public & Privates Institutions
- Research centers and universities
Whether you need a small-scale high tunnel or a more advanced glass structure with automation, our team can help design an institutional greenhouse adapted to training, experimentation, or research..
Why Growers Across Every Industry Choose Harnois
Harnois has been serving the greenhouse industry for over six decades. Our structures are engineered and manufactured in Quebec using exclusive oval steel tubing, 52% stronger than standard commercial-grade round steel, and Galvalume-coated for superior corrosion resistance in North American climates.
As a full-service partner, we manage every stage of your greenhouse project from design and engineering to manufacturing, delivery, and installation. Our in-house team of engineers, agronomists, and project managers works closely with growers in every industry to deliver structures built to your crop, your climate, and your operation.
Whatever industry you grow in, Harnois has the structure, the experience, and the team to help you build it right.