According to the Sustainable Cotton Project, buying one organic cotton T-shirt prevents the use of 1/3 pound of pesticides. This fall, sustainability comes in cozy fabrics, flattering cuts, and fun colors and patterns.

Built for an active lifestyle, Water Girl's fall line includes a series of comfy, versatile items made from organic cotton, chlorine-free wool, and recycled polyester. Vari hat and Volcano jacket; www.watergirlusa.com.

With hoodies, pants, and T-shirts decked with subtle graphic messages, Mission Playground matches a cutting-edge, youthful design sense with a rock-solid ecofriendly mission. The company uses organic cotton, recycled polyester, and fair-wage labor and donates 1 percent of all sales to environmental nonprofit organizations. Monarch recycled polyester track jacket; www.missionplayground.com.

Under the Canopy uses only the most ecologically responsible fibers—such as organic cotton, linen, and wool—and fair-wage labor to make its line of clothing. Happily, the company is equally uncompromising on the fashion front: This fall's sweaters are as flattering as they are cozy. Bhutan sweater; www.underthecanopy.com.

Indigenous Designs has a refined, sophisticated design sense and uses knitting cooperatives, fair trade practices, and sustainable materials such as organic cotton, alpaca, hemp, and natural dyes. Organic cotton fringe scarf, Organic cotton cuffed beanie cap, and Organic cotton gloves; www.indigenous designs.com.