More Outdoors: Caroling in the Canyon and more at Stebbins Cold Canyon Reserve.

• California’s Native Plants — A tour of the Mary Wattis Brown Garden, focusing on plants native to California’s Central Valley. Learn why these plants thrive in our regional ecosystem. 11 a.m. Saturday, Dec. 4, Buehler Alumni and Visitors Center.

• Walk With Warren — Explore the pleasures of the winter garden with Warren Roberts, the arboretum's longtime superintendent, now retired. Noon Wednesday, Dec. 8, gazebo.

• Folk Music Jam Session — Pull out your fiddles, guitars, mandolins, penny whistles, pipes, flutes, squeezeboxes — you name it! — and join your fellow musicians during the lunch hour for a little bluegrass, old-time, blues, Celtic, klezmer and other world music. All skill levels welcome. Listeners, too! Noon Friday, Dec. 10, Wyatt Deck.

• Why Do Some Trees Lose Their Leaves? — A look at the difference between evergreen and deciduous trees in the Shields Oak Grove. 11 a.m. Saturday, Dec. 11, gazebo.

All programs are free and open to the public. More information: (530) 752-4880 or arboretum.ucdavis.edu (for directions, click on “Plan Your Visit”).