Specialty Agriculture

Your high-value crop deserves a high-quality fertilizer. POLYON® controlled-release fertilizer is the answer for a cornucopia of fruit and vegetable varieties that could benefit from customized, targeted nutrition.

The first fertilizer of its kind.
POLYON® entered the market in 1992 as the extended-release “fertilizer of the future” allowing growers reliable, predictable control. With different polymer coating thicknesses, release times could be varied to fulfill any plant nutrition requirement under a variety of growing conditions and climates – with a single technology.

The best fertilizer technology - still. As the POLYON® production, sales and distribution partner from day one, Harrell’s helped spread the POLYON® “gospel” throughout the U.S. Today, our technology pros are evolving the science of plant nutrition by pioneering POLYON®centric custom fertilizer formulations for virtually anything that has roots.

The last fertilizer you’ll ever need. POLYON® is the smartest, tried-and-true investment you can make in the vitality and marketability of your crops. Explore the benefits and possibilities. Read the independent research. Talk to our loyal users. In the end, we think you’ll agree: when GREEN is in the bag, great results are in your future.


As the key ingredient in a customizable plant nutrient delivery system, POLYON® offers many possibilities:

  • Higher yields and higher quality fruit and vegetables.
  • Minimizes potential for a negative environmental impact.
  • Higher efficiency and potential reduction in application rate.
  • Reduced disease potential due to a more uniform and consistent plant nutrition delivery process.
  • Nutrient release unaffected by microbial activity and excessive soil moisture.
  • Nutrient release coincides with plant growth needs.
  • Excellent source of coated Nitrogen, Phosphate and Potassium.
  • Homogenous source of NPK in each granule.
  • Minor elements available.
  • Potential reduction in applications and labor.
  • Custom blended to your specific crop and agronomic conditions.
  • POLYON® technology is the most abrasion resistant coated product. Reduced catastrophic release potential. Reliable, predictable, durable.
  • Can be custom manufactured for a variety of crops and release periods.

Watch How Osmotic Diffusion Works

POLYON®. Feeding your success.

FOR 25 years, POLYON® from Harrell’s LLC has been America’s premier controlled release fertilizer for golf and sports turf, lawn and landscape, nursery, and agricultural applications.

Industry-proven, universally trusted. Used with confidence for its predictable performance, labor-saving and earth-friendly benefits. Supported by relationship-driven sales and technology professionals 100% committed to helping you achieve the best possible results.

No fertilizer on the market feeds your success like POLYON®. Let us prove it to you. Contact your Harrell’s Specialty Ag rep today to create a fertility program customized to your agronomic needs.

Our Vice President of Specialty Ag Sales and Marketing is Matt Shook. You may reach him here: mshook@harrells.com

Research & Development

Through our research and development initiatives at Harrell’s, we’re committed to developing innovative technologies to benefit our customers. Our research scientists test and analyze the latest industry products to make sure you get the best options available. We are constantly developing solutions to address current and future agronomic challenges and are passionate about maintaining turf and landscape health efficiently and effectively.


Leveraging technology is important to your success. At Harrell’s, we offer unique resources to save you time, money and help you reach your goals.

myHarrell’s Customer Portal – Relevant and timely history of your purchases, invoices and general account information at your fingertips. Sign up  today.

In addition to these web-based resources, we also have lots of other tools that will make your job a little easier.