I would suggest adding deciduous trees rather than more conifers if you want to grow trilliums, jacks and other woodland spring ephemerals. In nature, these plants get a good dose of sun for about 6 weeks in the spring before the trees leaf out. Conifers, with their constant shade, make growing such plants difficult.

Thanks Judy! I think you're right. The garden does get morning sun from the neighbour's yard behind the fence. We had been thinking about planting a limber pine and a few yews but maybe now we'll look at more understory trees and shrubs. There is a maple sapling starting already that I think I'll leave. Next, I think I'll heighten the fence with wire trellis and plant some sweet autumn clematis to cover the chain link.

This is exactly the kind of feedback I was hoping for... I didn't know that about woodland spring ephemerals. Thank you again!

One of the charms of woodland gardens is that little surprise plants show up among the larger ones you have listed - all of which sound good. If they will grow in your climate, consider devil's bit (one of the most charming woodland plants ever), celadine poppy, asarum, cyclamen, or phlox divaricata sprinkled here and there as little accents. Hepatica is a nice little plant too. Good luck - you're going to have a beautiful garden back there.

I have a similar problem. Western Washington. We just replaced a falling down, long neglected fence with a new chain link fence (on 2 sides of the property where a chain link was the best application). My neighbor and I are on a quest to "obscure" the fence. What to plant? The area is pretty much surrounded by very tall pines. It gets dappled sunlight for about 3 hours a day..... on a sunny day. The fence is 5 feet tall, and we would like to "hide" it.