Understanding seaweed extraction methods: What the research tells us

Seaweed extracts are a valuable tool, but when it comes to how they are processed, there’s often a belief that cold-pressed seaweed extracts are inherently superior to those produced using other extraction methods.

The reality is more nuanced, and research suggests that the extraction method does matter—but not always in the way it’s often presented.

Extraction matters, but it’s not that simple

The way seaweed is processed influences its composition, and different methods—whether cold-pressed, alkaline, or acidic extracted —can yield varying results.

But rather than assuming one method is always best, it’s more useful to understand how different extraction techniques impact the beneficial compounds within seaweed and their effect on turf.

What does the science say?

Trials looking at different extraction types have shown that alkaline-extracted seaweed can lead to significantly greater root length and root volume in turf, outperforming other extraction methods in certain studies.

However, this doesn’t mean that other methods, including cold-pressed extraction, don’t have their place—it simply highlights that not all seaweed extracts function in the same way.

This is important because it moves the conversation away from a ‘one-size-fits-all’ approach. Instead of focusing on a single processing method, the real takeaway is that the benefits of seaweed depend on the way it is extracted and how it interacts with turfgrass in practice.

Why this matters in everyday turf management

Greenkeepers and agronomists have used seaweed for generations, and its role in turf health is well established. The challenge is ensuring that the products used are supported by data, rather than just marketing claims.

When evaluating seaweed extracts, it can help to:

• Look for independent trial data that supports effectiveness.
• Understand what the extraction method is actually delivering.
• Consider how the product performs in real-world conditions over time.

No two turf surfaces are identical, and factors like soil type, climate, and maintenance practices all play a role in performance.

The key is to match the right product to the right situation, rather than relying on assumptions about which method should be best.

Balancing tradition with progress

One of the reasons myths and misconceptions persist in the turf industry is that they often sound logical and are repeated so frequently that they feel like established facts.

The belief that cold-pressed extraction is always superior is a great example of this—widely held, often cited, but not always backed by data. That doesn’t mean cold-pressed seaweed is ineffective, just that the science suggests we should be open to a broader view.

At ICL, we believe in providing practical, evidence-based insights to help turf managers make informed decisions.

Turf management is constantly evolving, and staying open to new information—whether it reinforces or challenges existing practices—is what drives progress.