asarum caudatum (native ginger), oxalis oregana, trillium, vancouveria hexandra, bunchberry, or woodland strawberry.

What grows great for me in similar conditions are: Lamium maculatum from Nancy series (stays compact height wise but spreads vigorously and is semi-evergreen), Gallium odoratum (fast spreader), Oxalis oreganum (spreads vigorously), Asarum europeum (beautiful shiny leaves but it is bothered by slugs), Epimedium of all kinds, Arisarum proboscideum (charming little curiosity, spreads very gently), Arum maculatum with strongly variegated leaves (can be invasive in zones 9 and up), Adiantum venustum (the cutest and daintiest groundcover fern), Cardamine trifolia, Disporum, Acorus gramineus 'Ogon' (evergreen, spreads gently), Convallaria majalis (regular, pink, variegated, spreads very fast)... There are so many plants that would love a moist shade. I suggest buying smaller plants that would be easier to plant if the soil is compact or full of roots. Digging in conditions like these is not fun. Also in shade you should mostly focus on foliage as not that many plants will give you months of bloom in shady conditions. Try golden or variegated plants to brighten up that shade and try different leaf forms like bold leaves of hosta to go with the lacy leaves of the ferns you already have there plus something spiky like shade loving grass.

I second Adiantum venustum, Himalayan maidenhair fern. It's semi-evergreen and is a good spreader but not invasive. Mine is under a hose bib so I know it does well in moist shade and semi-shade. I saw a large tree at Bloedel Reserve where the entire drip line was one mass of this fern. I also like variegated hakone grass. It's my go-to plant for filling in where I need some bright color. It can take quite a bit of sun too, so it would be good for the edge of your bed. I love variegated Solomon's seal, which gets about 18" high. I have it along with several hellebores and epimediums under trees. Toad lilies are also good spreaders, especially Tricyrtis 'Hatatogisa'. What about astilbe? I've grown large clumps of those and divided them. They need it quite moist though.

http://www.greatplantpicks.org/plantlists/view/94

Thanks for all the help.

Lily, The bunch berry sounds nice and I love Ginger, but I read that the snails do too.

Mike, The woodland strawberry is very pretty. I will take a look at that.

Enith, what a fantastic plant list. I had lamium (Nancy) in Iowa and I really like the foliage and pink flowers, but it petered out after a couple years. Maybe it would like the Portland location better. Is there a particular epimedium you like? There are so many to choose from at a mail order nursery located in Salem!

May-flowers, The maidenhair fern is really cute. What exactly does semi evergreen mean in Portland? It sounds like the growing conditions there would be favorable.

I do have some Hakone grass, but I think it would be too tall along the border. I want something short along the border, but it is my all time favorite grass.

I will be checking this website a lot since we are new to the Northwest having lived in Iowa (zone 4 and a totally shaded backyard) for the last 35 years. Everything is so green here which I love.

I keep picturing a short ground cover in the area, because just on the other side are more ferns and hosta which I want to be able to see. Also a trillium and hellebores, but I think I need more trilliums. And that toad lily is really pretty. I am in trouble, too many good choices!

I like the yellow flowered epimedium, deer don't eat it and the bright new leaves are very pleasing. I whack the leaves off in February to see the flowers, then the new leaves come quickly. Also the Hakone Grass is beautiful. I guess it depends upon the texture you want.

Karenseb, oh my, where do I start with my favorite Epimedium? I started collecting them about a year ago, have about 35 different kinds and love almost every single one of them :-) Because you need to cover pretty large area I suggest you be practical and choose something easy to find and cheap like E. x versicolor 'Sulphureum' and 'Neosulphureum' or E.rubrum. Epimediums are becoming more and more popular and some of them can fetch pretty high prices for a small 3" pot.
As for Lamium, by many in PNW it's considered even a little too happy. It will grow, it will spread and a little piece of each clump will stay in leaf during Winter and that is what I consider semi-evergreen. In Woodinville, WA it never completely disappears and we are a tad cooler here than you are in Portland.
Enjoy finding your favorite groundcover!

I was checking prices of the epimedium online and they seem very expensive if you want to use it as a ground cover. Is there a local store that carries them at a reasonable price?

Thanks Enith, I was missed your post before I posted mine.

Is the lamium too happy in Portland in that it is invasive or spreads beyond control? I like it's shortness and want a ground cover that looks good with ferns,small hosta and maybe some coral bells. The area is mostly shade but along a 2 to 3 foot section near the stone path it is mostly sun.

Are the epimediums similar to trillium in that they stay in a clump?

I never complained about Lamium's vigor. I needed a fast coverage for shade and it worked fine for me but it did pop in few places on its own, even between cracks on my brick patio. I transplanted these new plants to new places and it saved me a lot of money. I noticed that in a little dryer soil it's much less vigorous. I wouldn't say it spreads beyond control but that's my opinion and some might disagree.

I live in Woodinville, WA and purchase majority of my plants from local nurseries. However, one of the wholesalers that sells to these nurseries is company from Portland called Xera Plants. I remember a few E. kinds I bought last year with their tags: 'Enchantress', 'Yubae', 'Pierre's Purple', 'Purple Prince', E. omiense. I think they were 7.99 per 3" pot but it's possible that buying directly from a grower you could get better price. I suggest you do some research on E. as some of them are runners (not clumpers) and spread a little faster thus making better groundcover. Plant Delights Nursery has one awesome article on E., I suggest you start right there and it might help you choose.

Article about Epimedium

I have a large clump of Sulphureum and I'd recommend it as a vigorous grower. I also have Lilafee, which has large heart-shaped leaves and purple flowers. Both are blooming now. I think it is rubrum that isn't very vigorous for me, and I've had it several years. It's still less than a foot wide. Lamium starts to look a little brown after it blooms, but mine has always gotten some sun.

The Himalayan fern stays green through winter, but with some browning. I cut mine back a few weeks ago and have all new bronzey growth.

Check out the Hardy Plant Society's sale, which is in April. Many of the local specialty nurseries will be there. I've bought a lot of shade plants there and not paid a lot, but that was when they were in Hillsboro. They moved to Portland a few years ago, so things may have changed. There's also a master gardener's sale at the Clackamas County Fairgrounds, which I've heard is good. Farmer's markets often have plants too.

Word of advice--try to do most of your planting in fall. The ground is drier and easier to work and the plants establish well with the winter rains. Plant selection is better in spring though, but you can purchase your perennials now, repot, and plant out in fall.

http://www.hardyplantsociety.org/hortlandia

http://www.clackamascountymastergardeners.org/SpringGardenFair.htm

Ajuga.

Thanks for all your help. I am going with maidenhair fern as a ground cover. How far back do you cut it in the spring? How tall is your Maidenhair fern. The ones I bought are very small and short. Hopefully they will like the area and spread.

Mine is maybe 4-6 inches high. I cut all the fronds to the ground in early Spring.

Thanks Enith!

Same here. You might mow it on a dry February day as it won't be long before the new fronds are up.