During World War 1, a Great Britain under threat began sending clippings of its most prized rose hybrids to a newly created garden sanctuary high in Portland's West Hills. Today, the 4.5–acre Portland International Rose Test Garden boasts more than 10,000 individual plants representing about 650 rose varieties—some of which bloom well into October.

The terraced garden attracts nearly 700,000 visitors a year who revel in sweet scents and sweeping views. One of them, famously, was Portland writer Katherine Dunn. From a 2014 WIRED article: 

Dunn recalls the moment when she began writing Geek Love. It was the late ’70s. “My son was about 7 or 8 years old. I’m a big walker. I like to take long walks and I like to have company. And one summer day, I said to my son, ‘C’mon, let’s take a walk. I’m going to go to the rose garden.’ He didn’t want to, he wanted to stay and play with his friends. So I went out on my walk and was feeling a little miffed at him. I came to the big experimental rose garden in Washington Park in Portland, way on the top of the hill. I sat on the brick steps there and looked out at all these hundreds of varieties of roses. Each of which had been bred very carefully for particular qualities: Different colors, shapes, and scents, one color on the inside of the petal, another color on the outside. I started thinking about a topic that had engaged me for a long time, nature vs. nurture, and about the manipulation of genetic heritage. It occurred to me that I could have designed a more obedient son."

A centennial celebration, 100 Years of Roses, will take place 11 a.m.–8:30 p.m. on Saturday, August 26. Highlights include free cupcakes, a special Salt & Straw raspberry, rose, and matcha tea sherbet, and a 6:30 p.m. alfresco concert from Pilón de Azucar. To help keep the winding street of Washington Park relatively car-free, Trimet will hand out 1,500 free passenger tickets to the event at the SmartPark at SW 10th and Morrison.