Companion plants for Turtlehead
Turtlehead blooms from August through September. It wants part sun and high water. The 8 companion pairings below each state why the pairing works.
Blooming before Turtlehead opens

Rhododendron
Takes part sun to part shade and moderate to high water; blooms in late spring, before this one opens; both are strong pollinator plants, and they feed in different months; evergreen, so the bed keeps its shape through winter.

Astilbe
Takes part sun to part shade and high water; blooms in early summer, before this one opens; both are strong pollinator plants, and they feed in different months; echoes the pink.

Japanese Stewartia
Shares part sun and moderate to high water; blooms in early summer, before this one opens; both are strong pollinator plants, and they feed in different months; taller at 16 ft, for the layer behind it.

Foxglove
Takes part sun to part shade and moderate to high water; blooms in late spring, before this one opens; both are strong pollinator plants, and they feed in different months; taller at 4 ft, for the layer behind it.

Beautyberry
Shares part sun and moderate to high water; blooms in early summer, before this one opens; both are strong pollinator plants, and they feed in different months; taller at 5 ft, for the layer behind it.

Flowering Dogwood
Takes part sun to part shade and moderate to high water; blooms in mid spring, before this one opens; both are strong pollinator plants, and they feed in different months; stands well above at 23 ft, a canopy to plant beneath.
Blooming alongside

Winterberry
Takes full sun to part sun and high water; blooms in mid fall as this one finishes; both are strong pollinator plants, and they feed in different months; taller at 6.5 ft, for the layer behind it.

Joe Pye Weed
Takes full sun to part sun and high water; both are strong pollinator plants; its seed heads stand through winter, for structure and the birds; taller at 6 ft, for the layer behind it.