That's a hard question, not being from your area. Sedum came to mind because it is in bloom now and my bees are all over it. I would suggest anything native, but that doesn't mean the bees will work it. You might contact your local county extension office for a list of plants that meet your requirements. That's your tax dollars working for you. Here in Kansas, they have volunteers that are just sitting and waiting for someone to call or walk in with a question during the months of March through October. The same might be true in Washington.