Stronger Crops in Tough Conditions: How Wollastonite Helps Plants Handle Stress

Across Ontario, farmers are no strangers to unpredictable weather and soil challenges. Whether it’s drought, disease pressure, or extreme cold, environmental stress can take a toll on yields, soil structure, and long-term farm productivity. But there’s a natural soil amendment that’s increasingly helping crops stand up to stress: wollastonite.

Rich in calcium and plant-available silicon, wollastonite strengthens plant defences from the inside out. When applied to soil, it improves drought tolerance, supports better sugar storage for cold resilience, and helps reduce the severity of common diseases. Backed by peer-reviewed studies, it’s a proven way to build resilience into the farm system without disrupting standard practices.

For Ontario farmers dealing with increasingly variable weather patterns, tight margins, and pressure to improve sustainability, wollastonite is a tool worth knowing about.

Drought Tolerance: Helping Plants Hold Water and Keep Growing

Drought stress reduces plant growth by limiting water availability, nutrient uptake, and the plant’s ability to photosynthesise. Silicon helps crops manage these challenges by reducing transpirational water loss, enhancing root function, and improving osmotic balance.

A 2020 study tested cantaloupes under three moisture regimes: 100%, 75%, and 50% field capacity. Even at just 50% moisture, silicon-treated plants maintained stronger growth compared to controls. The researchers found:

– Up to 27% higher fruit yields at 75% field capacity

– Better water-use efficiency across all treatments

– Enhanced quality: thicker fruit flesh and higher sugar content

While this was a greenhouse study, the underlying mechanisms apply broadly: silicon helps plants regulate stomatal opening, conserve water, and maintain internal turgor. In dry summers or under inconsistent rainfall, crops supported by wollastonite are better equipped to continue growing and producing.

Therefore, applying wollastonite ahead of dry spells could help safeguard yield by supporting the plant’s internal water management and stress response.

Cold Tolerance: Supporting Plant Health in Harsh Winters

Research at the Hubbard Brook Experimental Forest in New Hampshire used wollastonite to restore soil calcium levels and observe long-term effects on red spruce. The trees treated with wollastonite showed significantly greater cold tolerance, measured by:

– Higher sugar storage in foliage

– Increased antioxidant activity (APX enzymes)

– Improved winter injury resistance

Sugars act as a natural antifreeze in plants, and antioxidants reduce cellular damage during temperature fluctuations. Wollastonite not only increased sugar concentrations (glucose, fructose, sucrose) but also helped maintain higher APX activity, particularly in winter months when plants are most vulnerable.

These benefits translate directly to overwintering crops, perennials, and even early spring seedlings. Applying wollastonite ahead of winter may improve survival rates and reduce cold injury across various species.

Disease Resistance: A Natural Line of Defence

Silicon has been studied extensively for its ability to reduce disease severity across a range of crops. The mechanisms are twofold:

1. Physical: Silicon deposits in the plant epidermis make it harder for pathogens to enter.

2. Biochemical: Silicon can trigger the plant’s defence responses, activating stress signalling pathways even before infection sets in.

In greenhouse trials, pumpkins grown in soil amended with wollastonite showed:

– Reduced severity of powdery mildew

– Increased silicon content in tissue

– Stronger resistance at moderate application rates (3.13 and 6.25 tons/acre)

Tomatoes treated with silicon were more resistant to Fusarium Crown and Root Rot, a major fungal disease. The treatment slowed the pathogen’s movement from roots to stems, helping limit yield loss and plant death.

These results reduce the need for repeated fungicide applications and support more resilient cropping systems. For organic growers, this can be a game-changer as wollastonite is approved for use in organic systems.

How It Works: The Science Behind the Benefits

Wollastonite (CaSiO₃) is a naturally occurring mineral that dissolves gradually in soil, releasing two important nutrients:

 – Calcium (Ca): Supports root development, improves nutrient uptake, and helps regulate sugar production.

– Silicon (Si): Enhances cell wall strength, reduces water loss, and activates stress-response pathways.

Although not classed as an essential nutrient, silicon is now recognised as a “beneficial element” for many crops. Studies have shown that silicon plays a role in modulating stress-related genes, triggering antioxidant production, and even enhancing the activity of defensive enzymes like peroxidase and phenylalanine ammonia-lyase.

Silicon may act like a secondary messenger, helping the plant recognise stress earlier and respond more quickly. These biochemical shifts can lead to measurable gains in yield, plant health, and quality.

Timing and Application Rates: What Ontario Farmers Need to Know

For stress resistance, timing matters. Wollastonite is most effective when applied before stress occurs, not after the damage is done.

Here are some practical guidelines based on field and pot trials:

– For disease resistance (e.g. powdery mildew): Apply in early spring.

– For pH and general soil health: Similar to lime, wollastonite helps raise pH gradually while delivering silicon.

– For drought and cold tolerance: Apply ahead of the growing season or before winter dormancy to build up internal reserves.

Unlike lime, wollastonite continues to release silicon over time, making it a longer-lasting investment in soil health. It’s also safe to use with most standard equipment – no special machinery required.

UNDO’s Farmer Program: Through our Canadian farmer program, UNDO covers 100% of the material cost of wollastonite. The only cost to farmers is trucking. We provide logistics support and coordinate spreading, ensuring it fits seamlessly into your operations.

What the Research Shows: A Quick Summary

– Wheat trials: Applying calcium silicate at 300 kg/ha significantly improved shoot biomass, root weight, and tiller count. Treated wheat plants also showed higher chlorophyll content, better relative water content, and stronger physiological responses under stress.

– Leaf tissue analysis: Silicon-treated wheat had higher Si concentrations, indicating successful uptake and internal redistribution, key to activating drought and disease resistance pathways.

– Root development: Increased root weight and improved plant vigour suggest that silicon supports early establishment and nutrient uptake, especially under dry or compacted soil conditions.

– Photosynthetic efficiency: Higher chlorophyll levels and membrane stability in treated plants point to improved photosynthesis and better performance during periods of environmental stress.

Taken together, these results show that calcium silicate materials like wollastonite can support resilience in field crops like wheat, offering a practical tool to reduce risk and maintain yield when conditions turn against the crop.

Why Ontario Farmers Are Turning to Wollastonite

Wollastonite has already been applied across more than 100 Ontario farms through UNDO’s program, covering over 12,355 acres. The response from farmers has been overwhelmingly positive.

Our team coordinates spreading and measurement, working closely with scientists from the University of Guelph, the University of Washington, and Yale to monitor results. We also maintain experimental plots at Simcoe Research Station, tracking soil and crop outcomes in real-world conditions.

With support from buyers like Microsoft and British Airways, we’re scaling up efforts to bring this program to more Canadian farms.

A Practical Tool for Changing Conditions

Today’s farming environment demands more than just high-yield varieties and good luck with the weather. With unpredictable seasons, increasing disease pressure, and climate variability, tools that improve stress tolerance are no longer optional; they’re essential.

Wollastonite doesn’t just benefit soil chemistry. It equips plants to handle what’s coming: dry spells, spring frosts, pathogen outbreaks. With proven benefits across multiple stress types, it offers an opportunity to farm smarter, not harder.

Our mission is to support Canadian farmers with tools grounded in science and practical on the ground solutions. Backed by research, easy to apply, and available at no material cost through our farmer program, it’s helping growers across Ontario prepare for the future.

If you’re interested in joining the UNDO Farmer Program or learning more about how wollastonite can support your land, reach out today.

Let’s build stronger, more resilient farms together.

Interested in trying wollastonite on your farm?

UNDO’s Farmer Program covers the full cost of the material and spreading support, you just cover trucking. Get in touch to learn more or register your interest.

Speak to our team