I have about 100 feet of flowerbed that follows a damp drainage path. The area is 100% in the sun, no shade. I would like to plant some plants along this flowerbed that don't "spread" over time - can tolerate the damp soil of the drainage area, bloom, and come back every year.
Separately - at the end of this bed, where it actually goes towards the drain, I would like to plant some kind of spreading moss or something that blooms and would spread so that it eventually can cover the drain. That area is also on a bit of an incline.
The top soil is kind of low, and shale-y, so I guess I will have to dig a hole and put in some topsoil at each planting location? The climate is near the Washington DC area.
Any ideas on what could make this look great? I would also like any ideas on the right kind of edging for the outside edges of this bed. Here are some pictures