Understanding Biostimulants: An Overview Of The Major Groups

For many turf managers the focus is usually on the chemical and physical environment around the plant—soil tests, water quality, nutrition and protection. But biostimulants add a completely different layer, one that is harder to measure but increasingly recognised for its influence on plant strength, stress tolerance and overall turf resilience. Because the benefits are often indirect, biostimulants can feel complex, yet understanding the main groups makes it far easier to use them effectively.

What Biostimulants Are and the Major Groups

Biostimulants include substances that trigger favourable plant responses such as improved growth, stronger roots or enhanced stress tolerance. In turf, the most relevant types fall into a few clear categories:

Plant hormones, kelps and seaweed extracts:
Auxins, cytokinins and gibberellins regulate everything from root growth to cell division and elongation. Seaweed extracts derived from Ascophyllum nodosum or Ecklonia maxima contain small, highly active quantities of these compounds. Even small doses can influence development, although imbalance or over-application may have the opposite effect.

Humic and fulvic substances:
These natural organic compounds improve soil structure, oxygen availability and nutrient retention. Fulvics, because of their smaller molecular size, move more easily through leaves and roots and can improve the availability of N, P and K.

Protein hydrolysates:
Amino acids support turf during abiotic stress, assist microbiology in low-organic soils and can help unlock bound nutrients. These are useful where root function is compromised or where sand-based profiles struggle to hold nutrition.

Beneficial bacteria and fungi:
Species such as Bacillus and Trichoderma improve nutrient cycling, water access and natural disease resistance. Mycorrhizal fungi, for example, expand the functional surface area of the root system and strengthen the rhizosphere.

How These Components Influence Turf Performance

Biostimulants don’t replace good agronomy—they amplify it. Their indirect effects often show up as:

• improved nutrient efficiency

• stronger root development and faster recovery

• better water relations, reducing wilting and stress

• enhanced microbial diversity and soil resilience

Seaweed extracts often support rooting and stress tolerance; humics stabilise nutrient programs; hydrolysates strengthen the soil biome; and microbial products improve nutrient access during critical growth periods.

Where Biostimulants Fit in Seasonal Turf Programs

Biostimulants offer value at different points through the year. During summer, kelps, silica and hydrolysates help manage heat, drought and salt stress. Through winter, microbial products maintain root health when biological activity naturally slows. Around renovation periods, humics and seaweeds support recovery from cultivation and topdressing. On sand-based profiles, all groups help compensate for poor nutrient retention and reduced microbiology.

Across all seasons, the most successful programs use smaller, regular doses to maintain plant balance rather than large, infrequent applications.

How Nuturf can help you

Nuturf have developed a comprehensive liquid range that contains a number of biostimulant types and have various other granular fertiliser options that provide the opportunity to introduce biostimulants into your turf management regime. The FoliMAX liquid range either contains or has under development, a suite of options catering for the major biostimulant sub types named in this communication. Nuturf also offers products like Nutrismart either as straight granule for incorporation of humics or nutrismart as a component of other products to offer humics + NPK and TE nutrition options. This is an area Nuturf has embraced and is committed to further developing for our customers in future.