The city of Portland, Oregon is ideal for growing roses outdoors due to its location within the marine west coast climate region, its warm, dry summers and rainy but mild winters, and its heavy clay soils. Portland has been known as the City of Roses, or Rose City, since the late 19th or early 20th century, after Madame Caroline Testout, a large pink variety of hybrid tea rose bred in France, was introduced to the city. Thousands of rose bushes were planted, eventually lining 200 miles (320 km) of Portland's streets in preparation for the Lewis and Clark Centennial Exposition in 1905.