I have used a peony support and a cut off tomato cage and pea sticks....the cut off tomato cage worked well....the pea sticks looked better but were more trouble.
Linda C

Early in the season, you could try an arc or dome of wire mesh over it to hold the stems straighter. If done at the right time, the foliage should hide the arc.

It's one of the best plants in my garden. Drought tolerant, good foliage shape and color, low horizontal growth for the front of the border, very long bloom period. I like the relaxed sprawl.

If cut back early, will it grow shorter and straighter? ( like sedums or phlox)