What Are Biostimulants? Boosting Plant Growth Naturally

What Is a Biostimulant?

A biostimulant is a natural or biological substance added to plants or soil to enhance growth, improve nutrient uptake, and increase crop yield—but without acting as a direct source of nutrients or as a pesticide.

Unlike traditional fertilizers, which provide essential nutrients like nitrogen, phosphorus, and potassium, biostimulants work in non-nutritional ways. And unlike pesticides, they don’t kill pests, weeds, or diseases. Instead, they function more like vitamins for plants—stimulating internal processes that improve plant health and development.

Key Benefits of Using Biostimulants in Hydroponics

• Stimulate root growth
• Improve nutrient absorption
• Enhance stress resistance (e.g., drought, salinity)
• Boost photosynthesis
• Encourage microbial activity in the grow medium
• Trigger natural defense mechanisms

Common Types of Biostimulants

There are many types of biostimulants, each with its own unique mode of action. Here are some of the most commonly used:

1. Seaweed Extracts

Rich in natural growth hormones like cytokinins and auxins, seaweed extracts promote root and shoot development. They also improve plant tolerance to stress.

2. Amino Acids

Essential building blocks like glycine and tryptophan help in root formation and stimulate auxin production, which encourages vegetative growth.

3. Beneficial Microbes

These include living fungi and bacteria that interact with the root zone to improve nutrient uptake or consume ethylene precursors that slow growth.

4. Humic and Fulvic Acids

Extracted from natural organic materials like brown coal, humic acids enhance soil structure, increase microbial activity, and improve nutrient absorption.

5. Phosphites

While not a true form of phosphorus for plant nutrition, phosphites are known to stimulate root development and help plants resist certain diseases.

6. Triacontanol

This natural fatty alcohol—derived from beeswax or plant leaves—boosts photosynthesis and overall plant vigor.

7. Chitosan

A soluble derivative of chitin, found in insect shells and fungal walls, chitosan triggers immune responses in plants to help fight off disease.

8. Yucca Extract

Used primarily as a natural surfactant, yucca can open up the grow media, improving water retention and distribution.

Are Biostimulants Worth It?

Absolutely. When used correctly, biostimulants can enhance your nutrient program and lead to measurable improvements in plant health and yields. Products like Gold Leaf or Liquid Gold (for UK growers) can be effectively combined with biostimulants for even better results.

But be cautious: not all biostimulants are created equal. For every effective product, there are poor-quality imitations. Choosing the right biostimulant from a reputable manufacturer makes all the difference.

Final Thoughts

Biostimulants are a game-changing addition to any hydroponic or soil-based grow system. While they don’t replace nutrients or pest control, they do unlock a new level of plant performance that many growers overlook.

Article by Dr Russell Sharp

If you would like to keep up to date with subjects just like this, you can listen to both our podcasts! Links can be found bellow:

Hydroponics Daily Podcast: https://open.spotify.com/show/207T7p7fw9sPjINfSjVXW2

Cereal Killers Podcast: https://t.co/eSEbBkTVHl