I like upright things: early liatris, lilies, glads, then later on,cushiony lower things like mums and asters. But mostly, I like dahlias :)

What about Roses?...I'm planning on adding Dahlias to my Rose beds (here and there) My two favorites together.

The only trouble with trying to companion a dahlia is ...just where the heck is the dahlia going to stop growing.
A plant put in the wrong exposure next to a dahlia plant might be one that is needing to grow well in shade.

Personally, I have monarda growing next to 4 dahlia plants....that is, when I put them back into the ground..and the monarda I have to keep from growing into the dahlia....but that's a simple matter.
In front...toward more of the sun, I have an Annabelle hydrangea.
My iris, lilies, peonies, oriental poppies are all long gone from the scene so they don't offer any hindrance.
My yellow loosestrife in front is loose enough that the dahlia doesn't interfere with...and the black eye susans
are far enough away. Same with my oriental lilies.

All these are substantial plants in their own right so they tough it out with the dahlia.

thanks jeannie, your last point is well taken - I'll look for something that can stand its own ground - no pun intended.

Ashli, unless you are planning on planting dwarf and miniature dahlias that can be used as ground cover I don´t think that dahlias are a good companion for roses, they can get quite large and tall ( like that 10 ft tall 3 feet wide monster that grows every summer in my garden ) shading everything and anything around it, miniatures and dwarfs don´t grow that tall and wide. But still they are beautiful enough to be considered.