When should I use Vitalnova Prime and Guardian?

Vitalnova Prime and Vitalnova Guardian are two innovative biostimulant products designed to enhance plant health and resilience. Developed for use across all crop types (edible and non-edible), these products meet the growing demand for efficacious horticultural biostimulants that support sustainable high quality plant production.  Sam Rivers, ICL Technical Manager for Controls, looks at when to use them on the nursery.

Vitalnova Prime and Guardian are currently available in the UK and undergoing registration under the EU Fertilising Product Regulation (FPR 2019/1009) – a critical step ensuring they meet stringent standards for efficacy, safety, and sustainability. Fully compliant with the evolving definitions of biostimulants, both products are also approved for use in organic systems.

Vitalnova Prime

A root- and foliar-applied biostimulant derived from Saccharomyces cerevisiae (yeast), Vitalnova Prime is rich in amino acids and peptides. It functions as a natural elicitor, triggering induced systemic resistance (ISR) and upregulating key growth-supporting genes.

As such Vitalnova Prime is ideal for enhancing:

• Root establishment
• Stress resilience (drought, heat, waterlogging)
• General plant vigour.

Application Tip: Use as a root drench during transplanting to reduce shock and enhance early root development.

Vitalnova Guardian

A foliar-applied product, Guardian features a unique blend of polyketides from fermented yeast and essential micronutrients. This formulation strengthens leaf tissue and supports physiological function during stress events.

As such, Guardian is especially beneficial for:

• Foliar quality in interior plants (e.g. Fatsia, Hosta)
• Heat and drought mitigation in hanging baskets and other ornamentals
• Visual quality and resilience.

Application Tip: Apply as an intervention during early signs of foliar stress or during high-risk weather conditions.  Growers are finding it particularly helpful when building Vitalnova Guardian into an irrigation programme during periods of hot dry weather.

A guide to when to use

Meeting key biostimulant claims

Both Vitalnova Prime and Guardian support the EU’s recognised claims for biostimulants:

• Improved nutrient use efficiency – support uptake and utilisation
• Increased tolerance to abiotic stress – improves plant resilience
• Enhanced quality traits – better rooting, flowering, and top growth
• General principles – align with best practice in sustainable horticulture.

Word of caution

Avoid unsubstantiated claims! As demand grows, so does the risk of unregulated or misleading products. Many ‘miracle’ biostimulants lack proper validation. Before using a biostimulant product, I recommend asking yourself three questions:

• Is the product backed by trial data?
• Does it have clear classification (fertiliser, biostimulant, or PPP)?
• Are the claims legal and compliant?

It is worth noting that it is illegal to market biostimulants with pesticidal or curative claims (e.g. ‘prevents disease’) without proper PPP registration. Misuse puts crops, and businesses, at legal risk.

Backed by science, proven in practice

You can rest assured that Vitalnova Prime and Guardian have been rigorously tested on a range of ornamental crops. They offer consistent performance in improving plant health and establishment while meeting the new standards shaping the future of sustainable horticulture.