Now entering its 15th year, the Great Glass Pumpkin Patch will offer for sale 8,000 iridescent and opaque glass pumpkins made by about 35 artists.
"There's not one pumpkin that's like the other pumpkin," event spokeswoman Sharon Poynor said.
This year, for the first time, pumpkin collectors will be able to see how the glass pumpkins are made, Poynor said. Visitors will be able to watch artist Demetra Theofanous at work.
The pumpkins were made available for viewing on Tuesday and will remain on display until Friday. On Saturday and Sunday, they will be offered for sale.
The patch features about 1,000 more pumpkins than it did last year, said Rebecca Barbee, an arts producer at the Palo Alto Art Center, which is hosting the event.
"For some reason, people love glass pumpkins," she said. "They hold a special place in the hearts of people who enjoy collecting glass."
Barbee said the patch started 15 years ago with 750 glass pumpkins and sold out. She added that she's seen several glass pumpkin patches spring up across the U.S. that were inspired by the Palo Alto patch, including ones in Washington, Massachusetts, and Texas.
Pumpkin prices at the Palo Alto patch range from $25 to $700. The artists set the prices, and buyers are not allowed to bid on the pumpkins.
This year's festival will offer some unique pieces, including a glass pumpkin teapot, Barbee said.
The event runs from 10 a.m. to 5 p.m. through Sunday, but many people arrive much earlier to be the first in line once the pumpkins go on sale, Poyner said.
"There is a rush for them," Poyner said. "Sometimes people line up starting at 3 a.m."
Palo Alto Art Center Foundation members donating at least $250 to the center can attend a presale event at 5:30 p.m. Friday that includes food.
All viewings and sales are held at the Palo Alto Art Center at 1313 Newell Road.