Horticultural Alliance offers innovative, solution driven products to strengthen the business of our customers in the landscape, arbor, nursery and agricultural markets.

Put our 20+ years of experience, research and advancement to work for you. All DIEHARD(TM) plant and soil amendment products contain core ingredients like Mycorrhizae, beneficial bacteria and biostimulants to significantly boost nutrient uptake and plant vitality.

The company’s stated goal is “to change the way trees and shrubs are planted” – to reduce plant losses, help establish plants in unprecedented short times, and boost customer satisfaction with never before experienced results.

The company produces the highest quality, most complete products that are both environmentally sound and economically sensible. Commercial and residential users alike will achieve benefits they can see and measure.

Just as energy comes from the sun, our energy as a company comes from our customers. We are innovative, resourceful, and driven. And we are always mindful that the real measure of how good we are is the impact that we have on our customer’s bottom line. By focusing on yours, ours is strengthened as well.

Our Philosophy

Horticultural Alliance, Inc.’s philosophy is to market the best products possible for its markets, deal honestly and fairly with our customers by providing the best information and service possible to merit and earn their trust, and to deal fairly with our business associates.

Privacy Policy

More About Our Founder

James Quinn is described by Dr. Joseph B. Morton, Former Curator, International Culture Collection of Arbuscular Mycorrhizal Fungi (INVAM), West Virginia University, this way: “Jim is an exceptional horticulturalist who understands and appreciates the role of the Collection in promoting applications that improve commercialization of the fungi. He uses the Collection to assess the quality of his products and therefore clearly understands the Collection’s service mission. Most importantly, he provides a strong link to industry and ever-changing client groups.”

Mr. Quinn has a Bachelor of Science in Business Administration and a Master’s Degree in Business Administration from the University of Tennessee at Knoxville and is a Certified Public Accountant (retired).

Diehard - Soluble Powders Brochure