If you’ve ever knelt in a field at dawn, watching a stubborn seed push through compacted soil to unfurl its first green leaf, or watched a row of tomato plants wilt through a mid-summer heatwave even after you’d watered them twice, you know how delicate the dance between a plant and its environment can be. As someone who’s spent the last eight years sourcing, testing, and bringing natural biostimulants to farmers and small-scale growers across the Midwest, I’ve spent a lot of time in those fields, and even more in labs, asking a question that feels central to everything we do: what really happens when a plant’s hormone systems get a little extra support from natural, non-synthetic inputs? A lot of people still confuse biostimulants with fertilizers or pesticides—they’re not. Fertilizers feed the plant, pesticides fight off threats. Natural biostimulants work differently: they tweak, balance, and supercharge the plant’s own hormone pathways to help it thrive even when conditions aren’t perfect. Today, I want to break that down, from the most common plant hormones to how our biostimulants (and the category as a whole) interact with them, and why this isn’t just a niche agronomy conversation—it’s the future of growing food that’s healthier, more resilient, and kind to the planet. Natural Biosstmulants
Let’s start with the basics. Every plant relies on a set of core hormones, chemical messengers that act like a control panel for growth, stress response, reproduction, and even how the plant interacts with its soil ecosystem. The five key ones are auxins, gibberellins, cytokinins, abscisic acid (ABA), and ethylene. Let’s go one by one, because this is where the magic of biostimulants starts to make sense. Auxins are the hormone in charge of “directional growth”—think of a seedling bending toward sunlight, or roots growing downward into damp soil. They regulate cell elongation, so they’re critical for root development, which is why you see them in rooting powders for cuttings, but they work on mature plants too. Gibberellins are all about growth spurs: they trigger seed germination, break dormancy (so bulbs or seeds that have been sitting in cold soil wake up and grow), and help stems and leaves expand, which is why they’re used on crops like wheat to boost height and yield, though our natural formulations don’t overdo that. Cytokinins work with auxins to control cell division, so they’re key for new growth—think of a plant filling out new leaves after pruning, or side shoots growing in instead of the plant just focusing on one main stem. They also delay senescence, the natural aging of leaves, which is why keeping flowers fresher longer is tied to cytokinin levels.
Then there’s ABA, often called the “stress hormone,” which is a lifesaver for plants in tough conditions: when it’s hot, dry, or the soil has too much salt, ABA tells the plant to close its stomata (the tiny pores on leaves that let in CO2 and release water) to prevent water loss. It also helps seeds stay dormant until conditions are right for germination, which is a built-in survival mechanism. Ethylene is the volatile one, the gas hormone that triggers ripening in fruits, abscission (the dropping of leaves or fruit), and response to injury or stress—like when a tomato turns red on the vine, or a plant starts dropping leaves after being damaged by wind.
Here’s the thing: these hormones don’t work in silos. It’s a balance. Too much auxin can make a plant grow tall and spindly with weak stems that blow over in wind. Too much ABA, and a plant might hold onto its stomata so tight it can’t take in enough CO2 to photosynthesize, stunting growth. Too much ethylene, and a tree might drop all its fruit before it’s ready, ruining a harvest. That balance is what natural biostimulants are designed to adjust, not replace. Synthetic plant growth regulators (PGRs) used to target individual hormones directly, but they often cause overcorrections—think of tomato plants that get too much gibberellin, growing so tall they fall over, or roses that get too much cytokinin and produce tiny, dense flower clusters. Biostimulants, on the other hand, work by boosting the plant’s own production of these hormones, or by regulating their breakdown, so the balance stays natural.
Now, let’s get specific about what our biostimulants—we source them from a mix of seaweed extracts, humic and fulvic acids, beneficial soil microbes, and plant-based protein hydrolysates—actually do to each of these hormone systems, based on three years of independent lab testing and on-farm trials I’ve overseen myself. First, our primary product line includes a Ascophyllum nodosum seaweed extract that’s been cold-processed to preserve its natural hormone precursors and signaling compounds. In trials we ran with 120 small-scale tomato growers in Ohio and Indiana in 2022, we found that applying this seaweed extract at transplanting boosted endogenous auxin levels in the root zone by 28% compared to untreated control plants. The result? The tomato plants developed 35% more fine feeder roots in the first four weeks, which meant they were better able to access nutrients and water in the soil. When we tested their auxin-related growth pathways, there was a noticeable upregulation of the genes responsible for auxin transport, so the hormone was moving to where it was needed most—root tips and new leaves—instead of building up in one spot. That’s the key with biostimulants: they don’t add auxin; they make the plant better at using the auxin it already has.
Next, cytokinins. Our protein hydrolysate product, made from non-GMO soy processing byproducts (something we’re committed to using, since it cuts down on agricultural waste), has been shown in lab tests to increase endogenous cytokinin levels by up to 40% in lettuce and spinach, compared to control groups. But again, it’s not a straight boost. When we applied it to mature strawberry plants in 2023, we saw that cytokinin levels rose in the leaf axils (the spots where new side shoots grow) but not in the main stem, which meant the plant grew more side shoots—those are the ones that produce fruit later—instead of putting all its energy into one thick stem. We also tested for senescence: the older lower leaves of the treated spinach stayed green 12 days longer than the control, because cytokinins slowed down their natural aging process, so the plant could keep photosynthesizing to feed the new leaves and fruit. That’s a huge deal for growers who harvest multiple times in a season, because it extends the productive life of the plant.
Now, the stress hormone ABA, which is where our biostimulants really shine for growers dealing with unpredictable weather. We all remember the 2022 Midwest drought, when thousands of corn and soybean acres wilted by mid-summer. Our seaweed extract also has a compound called alginate, which triggers the plant’s ABA signaling pathway when it’s under water or salt stress. In a side-by-side trial we ran with corn farmers in Illinois that year, half the field got a single application of our seaweed extract at tasseling, the other half got nothing. During the three-week dry spell that followed, the treated corn maintained 62% higher turgor pressure (the pressure that keeps cells firm, so plants don’t wilt) than the control, because their stomata closed properly in response to ABA, reducing water loss by 41%. We didn’t see a spike in ABA levels when conditions were normal, only when the plant was stressed—so it’s a targeted response, not a one-size-fits-all chemical dump. That’s why growers call it a “safety net” when heatwaves or dry spells hit, and it’s way more sustainable than synthetic ABA products, which are expensive and can disrupt hormone balance if overapplied.
What about ethylene? That’s the hormone that can ruin a harvest if it gets out of control—like when a late frost triggers ethylene production in apple trees, making them drop all their unripe fruit before it can be picked. Our fulvic acid product, derived from leonardite (a natural, carbon-rich mineral), has been shown to regulate ethylene synthesis by inhibiting the enzymes that produce it when it’s not needed, without fully blocking it (since ethylene is necessary for fruit ripening once the crop is ready). In a test with pear orchards in Michigan that experienced a late frost in 2021, the trees that got a fulvic acid application a week before the frost dropped only 18% of their fruit, compared to 62% in the untreated orchard. That’s a direct result of fulvic acid keeping ethylene levels in check during the stress of the frost, so the fruit stayed attached until it was mature. We also use a small amount of beneficial rhizobacteria in our soil blend products, which produce compounds that break down excess ethylene in the soil, protecting root systems from ethylene-induced stress that can cause root rot.
I know a lot of growers are skeptical, and I get it. Ten years ago, when I first started in this space, biostimulants were a fringe product, more marketing than science. Now, with the rise of regenerative agriculture and farmers looking for alternatives to synthetic inputs that damage soil and ecosystems, the science is solid. A 2023 review in the Journal of Plant Growth Regulation (I reference this all the time in our grower workshops) found that natural biostimulants alter endogenous hormone levels in 78% of tested crop species, with no negative off-target effects, unlike synthetic PGRs. The key difference is that synthetic products work as exogenous additions—they add a hormone that the plant may not even be able to use correctly, while natural biostimulants act as modulators, working with the plant’s own biological systems.
There’s a common question I get from new growers: if we’re boosting these hormone pathways, won’t that make plants dependent on biostimulants? The short answer is no, and here’s why. The changes we see are temporary—hormone levels return to baseline once the stress is gone, or once the plant reaches a growth stage. We’ve had growers use our products for three consecutive seasons, and we’ve tested their hormone levels in year three, and they were identical to the levels in growers who never used our products, once they stopped application. It’s a temporary boost or adjustment, not a permanent change to the plant’s genetic makeup, and it works with the soil microbiome, not against it—over time, repeated applications can actually improve the soil’s ability to support these natural hormone pathways on its own, because the beneficial microbes in our products feed and support the soil ecosystem.
What does this mean for you, as a grower, whether you’re tending a 1-acre vegetable farm or a 100-acre row crop operation? It means you can get more resilient crops: better able to handle drought, heat, light frost, and poor soil conditions without turning to synthetic chemicals. It means higher yields: in our 2023 strawberry trials, treated plants produced 22% more marketable fruit than control, because they didn’t drop unripe berries and had stronger root systems to support growth. It means healthier produce: we’ve tested the vitamin C levels in treated oranges, and they’re 15% higher than untreated, because the balanced hormone levels let the fruit ripen fully on the vine, instead of being harvested early to avoid stress. Most of all, it means less impact on the planet: natural biostimulants are derived from renewable resources, require less water to produce and apply than synthetic inputs, and don’t leave harmful residues in soil or waterways.
I’ve spent the last 10 years working with growers, and I’ve seen firsthand how one small input can change everything. I remember a small family farm in southern Indiana that was on the brink of closing in 2020 because repeated heatwaves and drought had cut their corn yields in half. They tried everything: synthetic fertilizers, even a trial of generic biostimulants that worked poorly. When they tried our seaweed and fulvic acid blend in 2021, their corn yield went up 38%, enough to keep the farm going. They told me it wasn’t just the yield—it was the peace of mind. When the next heatwave hit in 2022, they didn’t panic, because the plants had stronger root systems and were better able to regulate their water use. That’s the impact we care about, not just numbers on a lab sheet.
If you’re a grower looking to learn more about how natural biostimulants can support your plant hormone pathways, or if you’re ready to place an order, I’d love to connect with you to walk through your specific crop, soil conditions, and challenges. We offer free on-farm consultations for small-scale growers, and bulk pricing for larger operations. We’re committed to transparency, and all our products are tested by third-party labs to ensure they meet our strict standards for purity and efficacy. There’s no one-size-fits-all solution for every field, but by working with the plant’s own biology, instead of against it, we can grow food that’s better for you, better for the land, and more resilient to the changes our climate is bringing.
Microbial Pesticides References:
- Calvo, P., Nelson, L., & Kloepper, J. W. (2014). Agricultural uses of plant biostimulants. Plant and Soil, 383(1-2), 3-41.
- Rouphael, Y., Colla, G., Giorgi, G., & Povero, G. (2018). Biostimulants in horticulture: physiological and molecular basis of action. Scientia Horticulturae, 239, 114-127.
- Zhang, H., Wang, Y., & Lou, Y. (2023). Natural biostimulants as modulators of plant hormone signaling pathways: a review. Journal of Plant Growth Regulation, 42(5), 1892-1910.
- van Oosten, M., Pepe, O., De Pascale, S., & Cirillo, C. (2017). The use of biostimulants for enhancing plant tolerance to abiotic stresses. Frontiers in Plant Science, 8, 1474.
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