What, When, Where

* Today: Slide-lecture on the gardens of Ireland, followed by a plant sale, 2:30 p.m., at the Huntington Botanical Gardens, 1151 Oxford Road, San Marino, (626) 405-2141. Adults, $8.50; seniors, $7; students $5; children, free.

* Friday-Sunday: “The Romance of Orchids” orchid show with displays by more than 65 commercial and amateur growers, plus a large sales area. 10 a.m.-5 p.m. Friday, 9 a.m.-5 p.m. on the weekend, at the Earl Warren Showgrounds Exhibit Building, Highway 101 and Las Positas Road, Santa Barbara, (805) 644-8413. Adults, $7; seniors and students, $5; children, $1.

* Saturday: Talk on Gold Rush-era roses, 10 a.m., at Rancho Los Cerritos Historic Site, 4600 Virginia Road, Long Beach, (562) 570-1755. $5.

* Saturday: Class on spring color in the native plant garden, 9 a.m.-noon, at the Theodore Payne Foundation, 10459 Tuxford St., Sun Valley. $30. To register: (818) 768-1802.

* Saturday: Class on making a California cottage garden, 11:30 a.m.-12:30 p.m., sponsored by the Manhattan Beach Botanical Garden. Class is not held at garden; for location, call (310) 796-0282. $10.

* Saturday-Sunday: “Winter Bulb Festival” with bulbs in bloom, talks and a plant sale, 10 a.m-3 p.m., at UC Irvine Arboretum, corner of Campus Drive and Jamboree Road, UC Irvine, (714) 824-5833. $2.

* Saturday-Sunday: African violet show and sale, noon-5 p.m. Saturday, 9 a.m.-3 p.m. Sunday, at the South Coast Botanic Garden, 26300 Crenshaw Blvd., Palos Verdes Peninsula, (310) 544-1948. Adults, $5; seniors and students, $3; children, $1.