Companion plants for Foxglove
Foxglove blooms from May through July. It wants part shade and moderate water. The 8 companion pairings below each state why the pairing works.
Blooming before Foxglove opens

Coloratus Wintercreeper
Shares part shade and moderate water; blooms in mid spring, before this one opens; lower at 8 in, for the front of the border; both are strong pollinator plants, and they feed in different months.

Tall Oregon Grape
Shares part shade and moderate water; blooms in early 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.

Windflower
Takes part sun to part shade and moderate water; blooms in early spring, before this one opens; low at 6 in, to carpet the ground beneath; both are strong pollinator plants, and they feed in different months.

Snowdrop
Shares part shade and moderate water; blooms in late winter, before this one opens; low at 5 in, to carpet the ground beneath; both are strong pollinator plants, and they feed in different months.
Taking over as Foxglove finishes

Zigzag Goldenrod
Shares part shade and moderate water; blooms in late summer as this one finishes; both are strong pollinator plants, and they feed in different months; its seed heads stand through winter, for structure and the birds.

Blue Wood Aster
Shares part shade and moderate water; blooms in late summer as this one finishes; both are strong pollinator plants, and they feed in different months; its seed heads stand through winter, for structure and the birds.

Cherry Berries Wintergreen
Shares part shade and moderate water; lower at 8 in, for the front of the border; overlaps, then carries the display into late summer; both are strong pollinator plants.
Blooming alongside

Woodland Stonecrop
Shares part shade and moderate water; lower at 8 in, for the front of the border; opens in mid spring and overlaps into this one's season; both are strong pollinator plants.