Why do so many from other regions comment on the mild climates of the west coast of California as if pleasant weather is a deficiency? If horrid summer heat and frigid winter cold were worth bragging about, not so many people would have been so eager to migrate here.
Contrary to popular belief, the four seasons, although considerably milder than in other regions, are enough to keep our gardens productive, dynamic and even colorful in all seasons. All sorts of deciduous plants and fruit trees get just enough chill in winter to bloom reliably in spring. The warming weather between winter and summer that gets most plants to bloom is what spring is all about. Summer is then warm enough for fruit and vegetables to develop. Then there is autumn, when so many deciduous plants turn flashy colors before winter dormancy.
Although the mild weather limits the choices, there are still a few plants to provide autumn foliar color. Actually, autumn is not so colorful locally primarily because the potential for color is not exploited like it is elsewhere. There are just so many other plants that do not turn color in autumn to choose from. Really, Vermont would be less colorful if palm trees grew there!
Sweetgum, Chinese pistache, flowering pear and maidenhair tree are the most reliable trees for autumn color. Maidenhair tree turns remarkably bright yellow. The others get the whole range from yellow to orange to red. Sweetgum also gets burgundy, and has the added advantage of holding foliage until it gets knocked off by wind or rain. Where the big, bright orange (and yummy) fruit that hangs through winter is desirable, Japanese persimmon is as colorful as Chinese pistache. (Persimmons are horribly messy if not harvested.) Various poplars, tulip tree and black walnut can almost get as bright yellow as maidenhair tree.
Crape myrtle and redbud are shrubby plants that provide good autumn color. Redbud turns clear yellow. Crape myrtle though, can also get bright orange and brownish red. Several of the Japanese maples, although not always as reliable, can actually get even more colorful if the weather is right. Boston ivy (which is actually related to grape) is the most colorful of climbing vines, but because it attaches directly to whatever it climbs, it is best on concrete walls that it will not damage.