Hi Yago,

I'm in a zone 5 area too. Hardy Perennials, native shrubs and trees are the best way to go. The Problem is you need to have something blooming all season long to keep them. Unfortunately you can only do that if you have, in my opinion, a large area planted over at least 1/2 acre. I've found it's best to go with multiple beds of perennials and have one large bed 8 x 5 dedicated to just annual "red" salvias like salvia coccinea. That way you can dig in that annual bed, add all kinds of composts and nutrients in the fall to breakdown over winter and you don't have to worry about damaging perennials in the process.

Here is a link that might be useful: native salvia coccinea

A good spring blooming perennial for shade is your native Columbine. Another is bleeding heart and Eastern Columbine. All three of these will do well in shade. the columbine will also self sow Then a nice area for salvia coccinea will carry you through the summer. If you have a place for a nice perennial vine, try coral honeysuckle. Mid to late summer I would go with cardinal flower (Lobelia cardinalis) They are very very thirsty plants but wil bloom in part sun but they are a bit taller than 2 1/2 ft. Monarda (Bee Balm) may also work well for you if you can keep it moist. It will bloom in sun or part sun. The variety 'Jacob's Cline' is less prone to powdery mildew

penny

Penny had some good suggestions. You might also try a southeastern woodland plant called Spigelia marilandica. I'm trying it this year for the first time. It's supposed to be very attractive to ruby-throats, at least, and does well in part to full shade. It's also not too tall. The only downside is that it's rated only to zone 5, so might be marginal in hardiness for your Colorado winters.

Here is a link that might be useful: Missouri Botanical Garden info page for Spigelia

Spigelia is an excellent recommendation also. I haven't grown it yet myself only b/c I haven't found it in a local nursery but is one I plan to add as I do have a lot of shade.

Penny

Yago and Penny, I thought this Spigelia link might interest you. I've ordered 3 plants from Avant Gardens. I'm also going to look for them this spring at a local nursery that specializes in perennials. They sometimes have unusual things. I've got a nice spot picked out--it catches an hour or two of morning sun, then shaded by the dappled light of a silver maple, then probably a couple more hours of direct sun and then shaded by the house after about 1pm. I hope they do well.

Plant Delights nursery is offering two varieties of Spigelia, one shorter and redder--called "Little Redhead." I was tempted to try some of both, but they were sooo expensive at Plant Delights that I had to pass and just get the regular form from Avant Gardens.

You'll notice in the link, Penny, that they are easily grown from seed. I don't want to count my Spigelias before they're grown, but if my plants survive and I get any seeds, maybe I could send you some this summer or fall. I don't think they're a hybrid, so should come true, possibly with the variations that you often see in seed grown plants.

Interested?

Here is a link that might be useful: Spigelia marilandica