Winter rose care
Roses grow well in the Willamette Valley. After all, Portland is known as "The City of Roses". However, that doesn't mean that roses are trouble free. The most common problems with roses here are black spot, rust, and powdery mildew.
To help control these problems, rake all fallen leaves, prune the plants part way in November to keep the canes from whipping around in winter winds. apply lime-sulfur and horticultural oil sprays. These will kill overwintering fungal spores and suffocate overwintering insect eggs. Follow the label on the containers for instructions on use.
Around Presidents' Day in February, prune the roses to the recommended height for your varieties.
In the spring, apply a slow-release fertilizer of your choice.
I am including a link to an OSU Extension Service bulletin, "Controlling Diseases and Aphids on your Roses". It has a handy rose care schedule on the final page.
Happy rose gardening. May you have a season filled with blooms.