Griffith Park Night Hike The Sierra Club leads fun and instructive two hour hikes through Griffith Park. Wear comfortable shoes and meet at the upper merry-go-round parking lot. Griffith Park, 4800 Carousel Drive, L.A. Tue.-Thu., 6:45 p.m. (213) 387-4287.
Monster Tomato and Pepper Sale More than 200 varieties of tomatoes and 100 varieties of pepper plants will be for sale at the largest tomato and pepper plant sale in Southern California. fullertonarboretum.org. Fullerton Arboretum, 1900 Associated Road Cal State Fullerton Campus, Fullerton. Fri.-next Sun., 9 a.m.-4 p.m. Free. (657) 278-3407.
Twilight Hikes Hike along the trails in the Santa Monica Mountains. Meet at the east end of the center's parking lot. Stoner Recreation Center, 1835 Stoner Ave., Westwood. Fri., 6:30 p.m. Free. (310) 253-9840.
The Green Expo Celebrate the environment, healthy living, community and social consciousness at this solar panel powered festival. Highlights include over 150 exhibitors, educational workshops, free food and beverages, children's activities, eco awareness, eco fashion show and more. www.thegreenexpo.net. Woodley Park, 6350 Woodley Ave., Van Nuys. Sat.-next Sun., 10 a.m.-6 p.m. Free. (619) 865-5904.
Orchid and Bonsai Show Annual cymbidium orchid sale and bonsai show. Potting demonstration, bark and fertilizer for sale. West Los Angeles Buddhist Temple, 2003 Corinth Ave., L.A. Sat., 10 a.m.-5 p.m.; next Sun., 10 a.m.-4 p.m. Free.
Tree Hugging Day II People of all ages are encouraged to take a moment on the spring equinox to hug a tree. Hug on your own or join the Alliance for Survival for the Public Group Tree Hug at noon. Palisades Park , Ocean and Colorado avenues, Santa Monica. Sat., noon. Free. (310) 399-1000.
Public Star Party The Los Angeles Astronomical Society joins the Los Angeles Sidewalk Astronomers for a program that introduces families to the sun, moon, visible planets and other celestial objects using a variety of professional telescopes. www.griffithobservatory.org. Griffith Observatory, 2800 E. Observatory Road, L.A. Sat., 2-9:45 p.m. Free. (213) 473-0800.