Halawa Xeriscape Garden, 527-6113: Free admission to garden of dry-land plants at Halawa Industrial Park 10 a.m.-2 p.m. Saturdays and Wednesdays. Guided tours are free on Thursdays and the last Saturday of each month; call 527-6113 for an appointment.

Hawaii Orchid Growers Association: Joining with the Honolulu Orchid Society, the groups will hold the society's 58th Annual Show and Sale, "A Symphony of Orchids," Oct. 16-20, Blaisdell.

On Oct. 18, the association will hold their conference featuring a panel discussion with some of Hawaii's top orchid producers plus six speakers. Cost of the conference, including lunch, is $75 before Aug. 31, $100 from Aug. 31-Sept. 15, and $125 thereafter. Room/car packages are available and the association will also give guided orchid nursery tours on Oahu and the Big Island.

For information, call Cassandra Phillips at 1-808-968-8825.

Ho'omaluhia Botanical Garden, 233-7323: Learn about rain forest plants 10 a.m. Saturdays and 1 p.m. Sundays. Free. Bring walking shoes, bug repellent, rain gear and a picnic.

Compost workshop, 9:30-11:30 a.m. fourth Saturday of the month. Bring walking shoes, insect repellent, rain gear and work gloves.

Kahala HydroGreenery, 735-8665: Hydroponic gardening class, 9-10:30 a.m. Saturdays. Free. Reservations, 735-8665.

Lyon Arboretum, 3860 Manoa Road, Honolulu, 988-7378: Annual plant and craft sale, 9 a.m.-2 p.m. Aug. 23, Blaisdell. Free admission. Registration required. Information: 988-7378.

Wahiawa Botanical Garden, 621-7321: Hands-on gardening, 9-11 a.m. Wednesdays. Free.