The Board of Water Supply will hold its 20th Anniversary Open House and Unthirsty Plant Sale from 9 a.m. to 3 p.m. Saturday at Halawa Xeriscape Garden.

There will be guided garden tours, xeriscape workshops, a mulch giveaway, keiki activities, keiki garden planting and the chance to win an $18,000 xeriscape garden makeover.

The xeriscape garden, at 99-1268 Iwaena St., displays xeric (dry) plants — those that need less water than many other popular plants. The garden opened to the public in September 1989 as a way to show residents how to reduce water use on lawns, gardens and landscaped areas.

Parking is available on Iwaena and 'Iwa'iwa streets, with free shuttles running from Iwaena Street.