How about adding some Liatris spicata?

Hmmm - Red Hot Poker (forget the botanical name!) New England Asters, Tropical Hibiscus, Hibiscus (http://en.wikipedia.org/wiki/Hibiscus) lilies, day lilies, Matricaria - check with a perennial group and see what you can come up with. Good luck.

Try some of those lime green tobacco (nicotiana) and gentian sage - those colors look beautiful with the pink and can grow up through the dahlias. Neither will support the dahlias - frankly I don't think much will because the stems get so heavy. Try pinching the plants early on so they bush out a little more - I had a Fannie Williams (now called something dutch) from Old House Gardens and it kept snapping off because it was too tall and top-heavy.

Thank you all for your ideas!

Due to my zone (7-8), some of them might be a bit hard to grow here, but I'll ask someone at Nursery next time I go there!

If I can find salvia which will remain somewhat green during winter, it would be great, too.

I have planted Liatris bulbs in different location for the first time this year. I'll see how they grow and decide if I want them in my dahlia bed as well.

All advices are very inspiring. Thank you !!!

-b

OOH YEAH! Lime green and pink look divine together! (thanks for the hint! ;-)