There are lots of websites with lists of plants that will thrive in shady locations. There are so many that you really need to do some homework. Study the plants to see which ones will do well in your zone and in your soil conditions, and which ones you like. There is also a Shade Gardening forum here on Garden Web, if I'm not mistaken. Here is a link that might be useful: plants for shade

I'll transfer the pics over here for you. Those appear to be mature Willows to me. You can see in the first picture that the roots are visible at the surface level and that the grass is having a difficult time growing in that area. Planting small unestablished Hosta in that area is going to be very difficult. You can't just raise the soil level. Firstly, you need to continue to be able to see the "flare" of the trunk at the soil level. If you cover that part of the trunk in soil you will eventually kill those trees. Also any amended soil you add will just attract the willow roots. They go for the good stuff. BTW, the moss merely means that your pH is low. If this were my yard, here is what I would do. 1. Take a close look at the shade/sun situation with these trees. 2. Reshape the bed making the area that gets morning sun/afternoon shade larger than the side that gets the opposite. 3. When planting closer to the trunks of the trees use either pots above ground, or root control grow bags. Link below. 4. Amend the soil in the areas I am going to plant in the ground. 5. Use the biggest Hostas I can find from Hosta specialty nurseries. 6. Water, water, water. Water by sprinkler over a large area that includes areas beyond the garden, so that the willows can get what they need without strangling your Hostas to get it. 7. Put down a thick mulch of wood chips over even a larger area than the garden. The grass is competing with the Willows for moisture also. Do you see in that pic where the grass is greener? That's where you might be able to plant in the ground. What you are planning to do, can be done, but it's difficult. In the battle of the roots, the Willows have an enormous advantage because they are so well established, while the Hostas will be just babies. It will take lots of care and water to achieve what you want with the garden and not damage/kill those trees. Steve Here is a link that might be useful: Planting using spin out bags

I have zone 5a, with frost again tonight. I agree to take it easy, and would not keep them on the window sill. The larger astilbes I have are up to 8 inches out of the ground and have not unfolded yet, but other smaller cultivars show nothing yet. I have newly received hostas potted up and outside, but will bring them into the garage tonight. You could do the same, bring them out into the cool windy air when the temperatures are up. Bernd

It's always amazing to me how old threads pop up years later! If you look at the dates I started the thread 9 years ago..lol. I don't even remember what culvers root is anymore. However, my gardens are way more extensive than they were 9 years! I don't even need any more plants....except maybe a few peonies, and a few.......