The New England Wild Flower Society has the largest native plant education program in the U.S., offering 250 courses year-round.  Many of the classes are located at The Garden in the Woods in Framingham.  They have classes for kids and families that include birding, weather watching, and holiday nature crafts.  The classes for adults include subjects such as pruning, planting native plants, and nature photography.  Check out their fall-winter catalog, as there is something there for everyone!