How about Black Cohosh (Cimicifuga racmosa)?

Excelent! I just looked it up on the web and it looks perfect for what I want to do.
Thanks so much
Carol

Aconite, aka monkshood.

Springcherry

Monkshood is poisonous. If you have young kiddos you'll wish to avoid it.

Its an annual but sometimes self-seeds -- Love lies bleeding. A tall redhead with long legs that flowers from June till frost.

Aconite is an easy plant that you rarely have to do stuff to so the fact that it is poisonous isnt that big a deal. Just put something less toxic in front of it so that its not too accessable. Many common garden plants are poisonous. Do you grow foxglove? Castor bean? I think maybe the hellebores. Anything in the mandrake family. Just wear gloves when you plant it.

Springcherry

Try japanese anemones - the tall, fall-blooming ones. Light pink and dark, or they come in white. The single flowered ones are the prettiest. One caution: they will always grow where you plant them, so be sure you want them there (every bit of root left behind will resprout). Water through their first summer if you plant this late in the year, but otherwise they take it pretty darn dry (that goes with having those deep, persistent roots,I guess). I'm afraid I don't know how hardy these are.

I've never planted monkshood because I have kids too. Who needs the anxiety? Other plants are poisonous too, I grant, but in terms of degree of poison, this one is too risky to have around by my estimation. It also blooms right when kids are most likely to be outside.