Is Seaweed the Next Eco-Friendly Farming Solution?

“There is no such thing as a silver bullet when it comes to farming organically,” says Joe Nielsen, general manager and director of winemaking at Sonoma’s Ram’s Gate Winery. “Without herbicides and synthetic chemicals, you need to shift your time horizon. You’re not going to see results overnight like you would with chemicals. But we’ve found that using seaweed, over time, has created healthier soils and vines, and ultimately, that leads to better wine.”

Using seaweed to make better wine may sound a bit…unusual…but it’s an eco-friendly farming solution more vintners are embracing. Seaweed’s role in providing food and habitats for scores of marine species, its ability to absorb carbon dioxide from the atmosphere and reduce ocean acidification—which in turn protects all of the inhabitants of the water—is frequently touted, though is still not fully understood. Now, scientists are studying how this powerful, nutrient-packed sea plant can help farmers.

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“Seaweed extracts provide a boost to the existing soil chemical processes and activities,” says David McClintock, a consultant at R&D Viticultural Services who studies the benefits of seaweed in vineyards and coauthored a paper titled “Effect of seaweed extract application on wine grape yield in Australia,” published in the Journal of Applied Phycology. “As a bio-stimulant, it increases soil biota and provides more efficient chemical uptake of nutrients from the soil.”

Spritzing seaweed extract before fruit set and later in the season enhances yield and sugar accumulation, he notes. If seaweed applications are timed prior to heat or frost events, they may provide additional layers of protection, McClintock says.

Mike Sinor, founding winemaker at Ancient Peaks in California’s Central Coast, uses seaweed like many of us use vitamins, yoga or exercise—as a powerful form of optimization. Like Nielsen, Sinor notes that seaweed isn’t a solo vineyard star, but instead a part of his holistic, chemical-free approach to farming.

“We use seaweed extract because it helps our vines uptake nutrients better,” he says. “It is also a little bit of a fertilizer as well as a mildew suppressant.”

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Seaweed extract can be applied to the soil or as a foliar spray. Nielsen applies the seaweed extract via the dripline, while Sinor sprays it on the leaves. “We used it on our soils at first, but now we use it directly on the leaves,” explains Sinor, adding that the vineyard team applies it to all 1,000 acres of grapes. “We’ve done all kinds of trials and comparisons between blocks, and we have seen the difference it makes in terms of boosting the plant’s overall health and level of resistance.” Farming without chemicals like the herbicide glyphosate—exposure of which has been linked by scientists at UC Berkeley to serious health effects, including liver cancer, diabetes and cardiovascular disease—is becoming a priority for more and more producers, especially as organizations like Napa Green will require members to phase out its use by 2026.

Seaweed doesn’t act as quickly as chemical inputs, so vintners employing the technique are investing in the long game. With regular use, seaweed has proven to enhance microbial stability, thus securing the vine’s ability to uptake vital nutrients and, as a result, produce healthier, more fruitful vines than synthetics ever will.

This article originally appeared in the June/July 2024 of Wine Enthusiast magazine. Click here to subscribe today!

Published: June 19, 2024