tall semi-shade perennial?
So last fall, I created a new flower bed in an area of the yard where it looked like the entire bed got sun most of the day. I planted varying height perennials that liked sun and didn't require a lot of water. It's doing nicely this year, but I noticed that the tree nearby shaded the back of the bed much more than I thought. I think the tree grew a bit more, as well as I didn't account for the changing sun exposure during the spring and early summer (I had been gauging it during August).
So my sun flowers (the wild variety - I love those, so I grabbed a couple of plants from a field and planted them) I put in the back are rather spindly and are flopping over. Am thinking I should put something else in place of them for next year - something that does better in semi-shade, and won't flop. Any ideas, for zone 5? I want something that gets tall, but not too wide, and of course, flowers.