On this first weekend of autumn, fruit harvesting is a topic to smack your lips about, and Saturday's Festival of Fruit at Pipers Orchard in Seattle's Carkeek Park is what Cheap Fun is all about. It's the kind of fun that grows on trees.

The annual event marks the 120th anniversary of the orchard, which was planted by Andrew W. Piper, who ran the Puget Sound Candy Factory until it burned in the Great Seattle Fire of 1889, and his wife, Minna Piper (the horticulturist of the family, at left in a historical photo of the orchard, above).

Some of the original trees remain, supplemented by dozens of newer fruit and nut trees planted by the city parks department and a citizen group, Friends of Pipers Orchard.

Most trees are apples, and cider pressing is on the agenda of fun Saturday (10 a.m.-1 p.m.), along with apple pie judging (10:45 a.m.) and a pie sale (at noon).

You can get smart, too. A landscape architect for the National Park Service will lecture on "Historic Orchards in America" at 10 a.m., followed by sessions of heirloom apple tasting and identification, talks on fruit foraging, and treeside presentations on topics ranging from pest protection to permaculture.

Festival of Fruit is 10 a.m.-2:30 p.m. Saturday at Carkeek Park Environmental Learning Center, 950 N.W. Carkeek Park Road, Seattle, and in Pipers Orchard, reached from the park's lower meadow parking lot. Free; cider and pies for sale.206-684-0877 or www.pipersorchard.org.