UW Botanic Gardens’ Center for Urban Horticulture (3501 NE 41st Street) is having a class called "Gardening with the Seasons: Winter" " on Wednesday from 7-8:30pm. The cost is $20.
The class information says:
Though it seems there isn't much to do in the garden over winter, dormant season tasks can set the stage for a good gardening year. When weather keeps us indoors, we can plan ahead for tasks and garden changes to be done in the months ahead.
When the weather is nice enough to spend time outdoors, it can be amazing how much we can actually take care of now. This session will cover dormant season pruning and transplanting for specific plant types, winter weeding and garden care, best tools and practices, and planning ahead for the new growing season.