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

Rosemary
Shares full sun and low to 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.

Rock Cress
Shares full sun and low to moderate water; blooms in mid spring, before this one opens; both offer pollinator forage, in different months; evergreen, so the bed keeps its shape through winter.

Flowering Crabapple
Shares full sun and moderate water; blooms in mid spring, before this one opens; both are strong pollinator plants, and they feed in different months; stands well above at 20 ft, a canopy to plant beneath.

Wisteria
Shares full sun and moderate water; blooms in mid spring, before this one opens; both are strong pollinator plants, and they feed in different months.

Viburnum
Shares full sun and moderate water; blooms in mid spring, before this one opens; both offer pollinator forage, in different months; taller at 6.5 ft, for the layer behind it.

Freesia
Shares full sun and moderate water; blooms in mid spring, before this one opens; both are strong pollinator plants, and they feed in different months.
Blooming alongside

False Indigo
Shares full sun and low to moderate water; opens in late spring and overlaps into this one's season; both are strong pollinator plants; its seed heads stand through winter, for structure and the birds.

Sea Thrift
Shares full sun and low to moderate water; opens in mid spring and overlaps into this one's season; evergreen, so the bed keeps its shape through winter; both offer pollinator forage.