If you do one thing, plant oaks,” says Nick Jensen, conservation program director of the California Native Plant Society. They support insects, birds and squirrels.

When you plant a native garden, you become a steward to your local ecosystem, creating a small seed bank that ensures a piece of evolutionary history will survive to the next generation of humans.

Learn about native plants for free from the experts April 26-27 at the L.A. Times Plants' Native Plant Booth at the Festival of Books.