Incredible Ŝ際玫瑰試驗園International Rose Test Garden 2023. More than 10,000 individual rose bushes bloom in the international rose test garden (irtg) from late may through october, representing over 610 different rose varieties. Web originally built to make a good impression on the lewis and clark expedition in 1905, the international rose test garden has since played an important role in rose conservation, botanical science, and portland culture—it’s the reason portland is nicknamed the city of.

The roses are quite lovely. The roses bloom from april through october with the. The rose garden is in washington park, and it is free to visit.