Sustainability

For Margaret Duckhorn, Napa Valley was first and foremost home. Her family lived here, and she cared deeply about the local landscape and community. Looking after both was a natural part of her life, and that approach continues to shape the winery’s work today.

Water and soil receive close attention in the vineyards. Drip irrigation is supported by measurements of soil moisture and vine water status, helping the team decide when to irrigate and how much water to apply. Mixtures of legumes, clover and other plants grow between the vine rows. They help protect the soil from erosion and improve its structure, while legumes also enrich it naturally with nitrogen.

Native oak woodlands, wildlife corridors and planted borders remain part of the vineyard landscape, providing habitats for beneficial insects. Three Palms and Marlee’s Vineyard also have nesting boxes for owls and other birds, which help control rodents and other vineyard pests. Encouraging their natural predators is one of the methods the winery uses to protect its vines.

These efforts extend to the winemaking facilities in St. Helena. Rooftop solar panels generate electricity that helps power the winery, including cooling during winemaking and ageing.