Recycle your secondhand construction materials, available on the cheap from Berkeley's Urban Ore

PHOTO BY BEN CHANEY

SUSTAINABLE BIODIESEL RETAILERS ALLIANCE

An association of biodiesel companies committed to providing fuel to those who already use it — and assistance for those who want to lead their diesel engines to greener fields. Go to any of the alliance's locations to fill up on biofuel or get help converting your vehicle to biodiesel. Biofuel Oasis in Berkeley, Dogpatch Biofuels, and People's Fuel Cooperative located in Rainbow Grocery are all part of this groovy green oil alternative. www.autopiabiofuels.com

Green your home

SAN FRANCISCO COMMUNITY POWER

Partnering with the San Francisco Department of the Environment, SFCP is a nonprofit that helps small businesses and low-income residents save money and reduce environmental impact. SFCP recently launched a free Green Home Assessment Audit initiative available to all city residents that helps improve home safety, disaster-preparedness (how timely), efficiency, and ecofriendliness. It also distributes vouchers for home improvements.

www.sfpower.org

BAYVIEW GREENWASTE

This benevolent mulch-making company donated all the material needed for sheet-mulching the magnificent Hayes Valley Farm and has contributed, free, to dozens of other community projects. Even the small-time urban grower can pick up mulch, compost, or soil amendment from its SF or Redwood City sites. It also delivers (for a small fee), so go ahead and rip out those invasive, inedible weeds in front of your house. Your own patch of nature awaits.

www.bayviewgreenwaste.com

CALIFORNIA NATIVE PLANT SOCIETY

Speaking of patches of nature ... visit this group's website for gardening tips, links, and a list of local nurseries that sell native plants.

www.cnps.org

RECYCLED MATERIAL BUILDING SUPPLIES

Before you build, paint, remodel, or so much as hammer in a nail, it's worth tripping to the Bay's building resource centers — second-life sites for construction debris and used building supplies. The East Bay's Urban Ore and The Reuse People host landscapes of pink toilets, claw foot tubs, and towering stacks of discontinued tile. Looking for some SF supplies? Try Building Resources in SF (www.buildingresources.org) or www.stopwaste.org.

Build your green community

SAN FRANCISCO GREEN FESTIVAL

Of course, being sustainable isn't all heavy lifting and culinary vigilance — environmental friendliness can be a fertile way to meet your like-minded neighbors. This weekend, trek to the city's largest green expo for more than 130 speakers, music, and exhibits featuring everything from Food Not Bombs to reclaimed redwood manufacturers.

Sat/9 10 a.m.–7 p.m.; Sun/10 11 a.m.–6 p.m., $5–$25. SF Concourse Exhibition Center, 635 Eighth St., SF. www.greenfestivals.org

SF GREEN MAP

A great online visual for people looking for the nearest community garden, recycling center, and so much more, this happy cartographic achievement documents our city by highlighting its bright green hubs of activity.

www.sfgreenmap.org