I've been seeing this post for a couple of months now and I re-read it tonight and realized what zone you're in. While I don't have a photo, how about a link. Have you ever considered Gunnera? It's a fantastic BOLD foliage plant that would cover up a drainage ditch or for that matter anything and it will do well in shade.

Here is a link that might be useful: Gunnera Photo

I live in zone 7, and thought about purchasing Gunnera, but was, what do you call it? Disenchanted by the reports I have from other growers in my zone, same city, who said it did not like our hot summers.

So far, I am growing Monkey Flower (mimulus ringens) in a bog in shade and it is flowering. You can also grow a lot of the aroid family members, elephant ears of different colors, in a shady bog.

Susan

this is what I have growing in NO direct sunlight, very shadded:
all of these are growing to full bloom and full size in direct mud:

1. cardinal flower
2. blue flag and yellow flag iris
3. water plantain
4. marsh marigold
5. pickerel plant; pickerel rush; pickerel weed
6. variagated sweetflag
7. water cellery
8. water clover, hardy
9. arrow arrum

10. bog arrum; water calla
11. some unidenfied flower, that may be a form of monkey flower - but white - of the genus: Lowes

now, the only thing that is not going crazy growing to MAXIMUM potential, are the 12. arrow heads - they are growing big only where planted in direct or partial sunlight.

so, rather then wasting your time with a listing or any further research, know that ALL OR ANY bog or marginal is going to do great in shade - unless we are talking about complete cut off from light - NO yellow - direct sunlight has ever hit those plants above for as much as a minute and they are growing great - they are in a corner of the yard under some pine or ceder type of trees.

NJBio, how long have you had them growing under those conditions?

since june - funny enough, i was looking at them today - there's even less light now as the foliage above has multiplied

still less sun - more growth - many blooms of pickerel weed