Companion plants for Clematis
Clematis blooms from May through September. It wants full sun and moderate water. The 8 companion pairings below each state why the pairing works.
Blooming before Clematis opens

Hyacinth
Shares full sun and moderate water; blooms in early spring, before this one opens; low at 10 in, to carpet the ground beneath; both offer pollinator forage, in different months.

Grape Hyacinth
Shares full sun and low to moderate water; blooms in early spring, before this one opens; low at 8 in, to carpet the ground beneath; both offer pollinator forage, in different months.

Eastern Redbud
Takes full sun to part sun and moderate water; blooms in mid spring, before this one opens; both offer pollinator forage, in different months; taller at 23 ft, for the layer behind it.

Flowering Cherry
Shares full sun and moderate water; blooms in mid spring, before this one opens; taller at 26 ft, for the layer behind it; both offer pollinator forage, in different months.
Taking over as Clematis finishes

Aster
Shares full sun and moderate water; overlaps, then carries the display into mid fall; its seed heads stand through winter, for structure and the birds; both offer pollinator forage.

Goldenrod
Shares full sun and low to moderate water; overlaps, then carries the display into mid fall; its seed heads stand through winter, for structure and the birds; both offer pollinator forage.
Blooming alongside

Sea Thrift
Shares full sun and low to moderate water; opens in mid spring and overlaps into this one's season; low at 8 in, to carpet the ground beneath; evergreen, so the bed keeps its shape through winter.

Pansy
Takes full sun to part sun and moderate water; opens in early spring and overlaps into this one's season; low at 8 in, to carpet the ground beneath; echoes the purple.