When every transaction was recorded by hand and remembered by trust, Max Underhill’s Farm Supply was establishing roots that would support generations of local farmers. What began as a small fertilizer operation in Port Burwell has grown into a multi-generational business that has adapted alongside the evolving needs of local growers.
In the early 1960’s, Max Underhill began selling fertilizer as an agent for C-I-L from a warehouse located on his farm in Port Burwell, Ontario. At that time, fertilizer was distributed in 100 lb. bags, with only a handful of common blends available to growers. As part of a new initiative, C-I-L sought partnerships with local agricultural stakeholders to establish fertilizer plants throughout rural communities.
In 1969, Max Underhill entered into a 50/50 joint venture with C-I-L’s Agromart Group and officially opened the doors of Max Underhill’s Farm Supply in 1970. The business initially focused on supplying bulk and bagged fertilizer to local farmers, many of whom primarily grew tobacco and corn.
In 1978, Max sold 50 percent of his ownership stake to John and Marnie Sebok, allowing him to focus on his farming and trucking operations. As agriculture in the region evolved, so did the business. Crop diversity increased, customer needs changed, and Max Underhill’s Farm Supply expanded its offerings to meet the demands of modern farming. Over time, services such as crop protection chemicals, fumigation, custom application, soil amendments, seed sales, sucker spraying, liquid fertilizer, and delivery services were introduced.
A new chapter began in 1999 when John and Marnie Sebok sold their shares to their sons, Jonathan and Andrew Sebok. Under their leadership, the company experienced continued growth and modernization while maintaining its strong family-oriented foundation.
Today, Underhill’s employs 34 full-time staff members across two locations, while also relying on additional seasonal employees during peak summer months. Technological advancements such as GPS mapping, crop scouting by foot and drone, and site-specific soil sampling have played a significant role in the company’s growth and have created new opportunities within the agricultural sector.
Community involvement has also remained a cornerstone of the business throughout its history. Underhill’s continues to support local schools, sponsor community sports teams and events, and organize food drives benefiting food banks and surrounding communities.
As of 2026, Jonathan and Andrew have begun transitioning leadership responsibilities to the next generation, ensuring the continued success of the family business for years to come. For more than 56 years, Max Underhill’s Farm Supply has remained committed to serving its customers, supporting its community, respecting the environment, and promoting safe and responsible agricultural practices while fostering a positive workplace culture in a strong, team focused environment.
