I never knew there were so many winter flowering plants until I took 'Identifying Woody Plant Material' at OSU. That class was two hours of walking around Corvallis learning to i.d. plants in all seasons. Walking after a professor speed walking like his butt was on fire! Yes, I was in better shape back then. I think over the three terms, we learned around 600 plants!
All of this talk of school is because, over the past 14 years, I have tried to have something blooming year round. It is possible, here in the Willamette Valley, due to our mild winters. There are some very hardy flowering plants that will also bloom in the northern tier states. It just takes some research.
One of the best websites to research plant material is the Oregon State University Plant Materials page. Wish Pat Breen had finished that website when I took the class. I love Michael Dirr's Manual of Woody Plants for trees and shrubs. It is full of information on the plant growth habits, growing zone, diseases and pests. Of course the Sunset Garden Guide for your area of the country, is a wonderful resource for choosing both woody plants and perennials.
Today, when I took the garbage out, I smelled the wonderul fragrance of Sarcococca confusa ,Sweet Box. This winter flowering shrub has tiny, inconsequential flowers. Boy, do they pack a huge fragrance! Let the weather warm up just a little and they will blow your socks off! During a final exam, the professor opened the windows. Everyone's head went up. "What is that?" asked a student. All the Turfies (guys who were in my same classes, but were going to be golf course greens managers) answered in unison, "Sarcacocca." I figure more than one of them planted this shrub on the course!
The Sweet Box is a nice graceful shrub to about five feet. There is another species, S. hookeriana var. humilis, that is a low growing ground cover. It was combined with Stewartia psuedocamellia outside the Science Building at Chemeketa Community College (CCC), The Stewartia, at 25 feet, with it's multi-trunks, and gray bark makes a good planting with the Sweet Box. The Stewartia has spring, summer (blooms), and fall interest; while the Sweet Box is the winter plant of note.
I also have violets blooming, Viola sp.. I will always remember a friend I made in Intro to Botany at CCC, whenever I smell violets. We traded plants. When we move this summer, I will be taking a pot of her violets with me.
Another plant, Helleborus niger, I got from a co-worker in the 1990 Census. She called it the 'ugly plant.' Called the 'Christmas Rose' or 'Lenten Rose', mine blooms white in the winter, turns purple in the spring, and white again in the fall. There are many hybrids and varieties of this popular garden plant.
Of course, what winter garden wouldn't be complete with out a camellia? Camellia japonica comes in red to pink to whte. Mine is pink with random white stripes. It is just gorgeous! I am trying to get a start from it to take with me. I have two other camellias, a red and a pink. They are common camellias that someone once refered to as 'Measles Plants.' Each to their own.
If you would like some winter vegetables you might like to try a winter cauliflower or a winter broccoli. Start them in July/August to transplant in September/October. Protect them from the north and east winds, otherwise these are tough plants. We ususally had our first harvest during February. They will continue to produce for a long time. Just one plant of each, and our neighbors would pretend they weren't home whenever they saw us with a basket or bag. ; )
Well, those are my winter flowering plants. There are many other plants out there for you to choose from. Puruse the web, books, catalogs, and ask about for plants that may work in you yard.