How Combining Advanced Substrate and Controlled Release Fertilizer Technologies Can Increase Your Bottom Line
August 18, 2025 
Photo: Profile Products
Profile Products recently announced new findings from its ongoing trials aimed at extending plant shelf life and reducing retail shrink. Greenhouse Grower Editor Brian Sparks recently caught up with Brandon White, applied R&D scientist, who has been leading those trials, to learn more about the key takeaways from these trials.
Brian Sparks: Can you tell me about the goals you had going into this research, and how the process went?
Brandon White: We started this work about two years ago with an initial focus on the use of our controlled release fertilizers (CRF) compared to water soluble fertilizers in the greenhouse market, and in particular the effect on retail plant quality. How can we show the benefits of controlled release fertilizers such as our Nutricote product, particularly when used with our HydraFiber full growing system? We really felt we could help growers not only produce the best quality plants, but maintain that quality through the full sales cycle and get more across the finish line.
We set out to do three trials, and we called the first one our mass balance study. We took our products versus our competitors and ran those out in containers without any plants to compare full nutrient release profilesOne group conducted in the lab to achieve a consistent 70°F and one group was conducted in greenhouse under common conditions (for North Carolina).For both groups, we looked at everything: all your typical plant nutrients, not just nitrogen, to see what those nutrient release curves look like.
Nutricote was the highest performer with the best overall releaseprofiles, displaying how it releases optimum nutrientlevels within the key production window while still leaving enough left over for retail and the consumer experience. From that we were able to look at fertilizer prices and break down how much nitrogen is actually released and what that dollar value looked like, or cost per bioavailable nitrogen. We wanted to show that when you pay a price for a premium product, it’s going to deliver and can still actually save you money. We showed that research in a recent webinar.
From there we did trials in the greenhouse using our CRF technologies, with six different species and three different container sizes. We did an early season, a mid season, and a late season in 2024. Again, our goal was to show how our CRFs maintain retail plant quality (i.e.shelf life) over water soluble to extend the sales window to help growers reduce shrink and drive more sales.
Overall, controlled release fertilizers extended plant quality better than water soluble in all container sizes, which we expected. We also expected those effects to play out more as the container size increases, including in 10-inch hanging baskets. We had a demo at Cultivate that showed those effects up to five weeks after plants were retail ready. That aligns well because the growers got more of an investment in that larger plant. It’s taking them longer to grow it in most cases, and they’re getting a higher margin for it.
Along with the container trials, we also did a drought study where we looked at an older industry standard mix of 80% peat and 20% perlite versus a common, newer industry standard mix of 60% peat and 40% HydraFiber, For each of these mixes, we grew some with water soluble and some with Nutricote. We grew those plants out with normal production practices and took them to the retail-ready stage, then cut the water off until we saw drought stress across the board. Then we rewatered all of them to recovery before doing a final dry down (to plant death) to observe how many days plants could hold acceptable quality before reaching that terminal wilting point. We took photos and wilt and quality ratings during these dry down periods.
We were able to show that HydraFiber gives growers more protection in common drought conditions and mitigates wilt effects by providing more easily available water. Nutricote, again over water soluble, also showed better protection against drought stress symptoms. When you combine both of those together, you see even more of an effect of mitigating this drought stress response. We demonstrated this at Cultivate and were able to show that even with four or five days without water, the plants still look good and more likely to be chosen by a consumer. And we did a fun booth survey that showed people were willing to pay more for better quality plants. -We also have a case study with Rockwell Farms and other growers who have seen these benefits in their own operations. That’s important for growers who sell at retail because while they don’t have control over everything, they can have some control over this variable.
Brian Sparks: Many growers are currently working on budgeting for the coming year. As they deal with higher input costs, how can this research help them navigate through that?
Brandon White: I think growers can realize a cost savings just from switching over to controlled release fertilizers in lots of cases. There’s plenty of independent studies done by universities that break down the cost of controlled release systems versus water soluble systems. The increased sell-through is just icing on the cake when you can add that money directly to your bottom line. We know we can’t eliminate shrink completely, but if we can help a grower reduce their shrink by 5%, that’s 5% more plants that they’re making money from.
Brian Sparks: What does the next phase of your research look like?
Brandon White: We already see that Nutricote is going to offer the most sustained nutrient release profile. We also know that HydraFiber helps delay wilting effects by providing more bioavailable water than perlite-based mixes without sacrificing air space. And while we still recommend using wetting agents with HydraFiber, it can still help with re-wettability of mixes compared to some other substrates. While we certainly aren’t done with the story on how we can further improve and add value for our customers in this space, water and nutrition are the big keys to success and we feel like we have solutions that can transform the way growers take plants through the retail channel.
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