I have several Viburnum that have been on the western side of my house for at least 30 years and they do quite well, even though they tend to get neglected and get blasted by wind as well as sun. These are the normal, large sized Viburnum.

The first shrub that came to mind when you mention winter interest was red twig dogwood, which has also survived on the wind and sun blasted side of my house for over 30 years, but it exceeds your height requirement too.

Potentilla have always been a tough, drought tolerant, sun loving small shrub that is about 3 feet. They bloom in oranges, yellows and white. They're not much to look at in the winter.

Some gallica roses stay under 4 feet, have lots of dark red hips in the winter, bloom in the spring, are quite cane hardy in cold, sun and wind, but they sucker like there's no tomorrow.

Thank you for the suggestions, cnetter.

Perhaps Viburnum will remain on my short list after all!

The red twig dogwood has possibilities, as I know it can be pruned to size, but I think it has a tendancy to sucker, as well. I have a white poplar (I did not plant it, just have to deal with it) behind this bed, one of the reasons for the morning time shade; I definitely don't need anything else that suckers!

I love old roses, but if the gallicas sucker as well....no thanks. I actually have an Rosa 'Erfurt' Musk Rose in this bed but it seems to struggle a bit; lots of die back every winter, it has been there for about 10 years of so and is still pretty small. I might try another small shrub rose there - I actually have some on order from High Country Roses and one of them might do the trick.

Holly

How about some kind of barberry? Some are fairly compact, and many do have 4-season interest. Some kinds of cotoneasters are similarly interesting and are fine with full sun.

I actually do have a red leaved barberry (unknown cultivar)growing on the edge of this bed; it was almost dead when I moved into this house (about 20 years ago)but I was able to "rescue" it and it has been thriving there ever since. It keeps strangers out of my yard, too. lol

A cotoneaster might be a good choice, if I can find an upright cultivar that doesn't get too tall; I think most of the spreading types would take over the bed, but I'll see what is available.

Thank you for the suggestions, polygonum.

Holly

Some other sun-lovers are a cross between shrubs and perennials. I don't know if they're quite what you're looking for, but have you considered rabbit brush, apache plume, sagebrush, leadplant, mock orange, waxflower, etc. Most are native plants that tolerate full sun and dry conditions.

Here are a couple of publications from Colorado Extension that discuss shrubs for Colorado gardens:

http://www.colostate.edu/Dept/CoopExt/4dmg/Trees/Shrubs/smshrubs.htm

http://www.ext.colostate.edu/pubs/garden/07422.html

http://www.colostate.edu/Dept/CoopExt/4dmg/Trees/Shrubs/shrubs.htm

Unfortunately, though a native shrub would probably be ideal, I have other plants in the bed, such as peonies and a rose, that prefer a bit more water than would any of the natives you mentioned. I try to be water-wise but I definitely don't have a xeric garden. :-(

I ended up getting a 'Little Devil' ninebark for the spot. Hopefully it won't be too close in color to the barberry, and will add some interest to the bed, though perhaps not the 4-season interest I was looking for. (Well, the exfoliating bark might add some winter interest, right?)

I may have another spot for the Waxflower, however; it also tolerates some shade and has wonderful fall color, from what I have read.

Thank you for the suggestions and the links, polygonum.

Holly