Plants that bloom in October in Zone 5 with blue flowers

Aster

The grand finale of the garden season. Essential for fall pollinators.

Big Bluestem

The signature grass of the tallgrass prairie, turning copper-bronze in fall with distinctive turkey-foot seed heads.

Butterfly Bush

Long, arching flower wands that butterflies absolutely lose their minds over.

Morning Glory

Fast-climbing vine with trumpets that open fresh every morning.

Prairie Sky Switchgrass

The bluest foliage of any switchgrass, with airy pink seed clouds drifting above in late summer.

Rose of Sharon

A cold-hardy hibiscus shrub (Hibiscus syriacus) with big tropical-looking blooms in lavender, pink, blue, white, or wine, opening late summer when most flowering shrubs are done.

Rozanne Geranium

Violet-blue saucer flowers on a sprawling mound that blooms from late spring until frost. The most awarded perennial geranium in history.

Russian Sage

Airy lavender clouds on silver stems. Thrives in heat and poor soil.