Beginner Gardening: What should I plant in this bed?, 1 by z28melissa

z28melissa wrote:
I've got this ivy-covered bed next to my pond. As you can see there is one yellow lily plant, and some montauk daisies that bloom in the fall. There's also a few yellow tulips scattered around. The bed is lined with rocks which the ivy is almost completely covering.

This bed is so bare looking the majority of the year, anyone have ideas on what to plant there? I do want to keep the ivy, I think it looks nice, so I was thinking an ornamental tree or two? And you can see how the ivy has grown down to the water line (excuse my weeds!)... should I trim that up to the edge of the bed or leave it spilling down like that? And what about the rocks between the bed and the grass, should I keep them covered in ivy or trim the ivy up to the inside of the rocks?

I'm pretty new to gardening and it's hard to imagine what will work and what won't, so ANY ideas are welcome! :)