About Horticultural Alliance

Rooted in Innovation. Growing with Nature.

Founded in 1997 in the heart of Sarasota, Florida, Horticultural Alliance, Inc. has been a trusted name in sustainable plant health and organic soil solutions for over two decades. We specialize in formulating cutting-edge products that combine mycorrhizal inoculants, beneficial bacteria, biostimulants, and water management gels—designed to support plant establishment, vitality, and long-term health.

Our mission is simple: to help plants thrive naturally, while giving landscapers, arborists, nurseries, and growers the tools they need to succeed. Through our signature DIEHARD™ product line, we’ve delivered high-performance organic amendments that promote stronger roots, better transplant survival, and increased drought resistance—all while enhancing soil biology.

In 2019, Horticultural Alliance proudly became a part of the Hello Nature Group, a global leader in sustainable agriculture. With Italpollina’s support and shared commitment to environmentally responsible practices, we’ve expanded our reach and strengthened our ability to serve the ever-evolving needs of the green industry.

From the beginning, our values have remained unchanged: integrity, quality, and service. We are dedicated to providing exceptional support, reliable information, and high-quality products that help our customers grow with confidence.

Whether you’re establishing a new landscape, managing urban trees, or cultivating specialty crops, Horticultural Alliance is your partner in sustainable plant care—where biology meets performance.