Plants that bloom in August in Zone 6 with blue flowers

Anise Hyssop

Lavender-blue spikes with licorice-scented foliage. A pollinator powerhouse that blooms for months.

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.

Borage

Star-shaped electric blue flowers that bees go absolutely wild for. Self-sows freely.

Butterfly Bush

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

Campanula

Open, nodding bells in clear blue on tall graceful stems. Self-sows into refined cottage garden drifts.

Cat's Meow Catmint

Tidy, dome-shaped habit that never flops open. Stays compact without shearing.

Catmint

Billowy lavender-blue haze that blooms all season if you shear it back.

Chaste Tree

Long lavender-blue spikes cover this heat-loving shrub all summer. One of the few shrubs that actually blooms in August.

Clematis

The queen of flowering vines. Over 300 species, something for every spot.

Endless Summer Hydrangea

Reblooms on old and new wood, so you get flowers even after a harsh winter. Color shifts with soil pH.

Globe Thistle

Perfectly spherical steel-blue globes on white stems that dry to perfection. Bees are absolutely obsessed.

Great Blue Lobelia

Intense blue flower spikes that hummingbirds and bumblebees fight over in late summer. The bolder, taller cousin of cardinal flower.

Hydrangea

Massive mophead blooms that shift color with soil pH. Showstoppers.

Lavender

Fragrant silver-green mounds beloved by bees and humans alike.

Monkshood

Deep indigo-blue hooded flowers on tall spikes in late summer. One of the few genuinely blue flowers that grows in shade.

Morning Glory

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

Mountain Bluebell

Sky-blue bell flowers on tall arching stems along mountain streams. The showy western cousin of Virginia Bluebell.

Nikko Blue Hydrangea

The classic blue mophead. Rich, true blue in acidic soil. A cottage garden essential.

Pickerelweed

Spikes of violet-blue flowers above glossy arrow-shaped leaves. Native pond and stream bank staple.

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.

Salvia

Vertical flower spikes that hummingbirds and bees cannot resist.

Sea Holly

Metallic blue bracts and cones turn the whole plant a vivid silvery-blue. Otherworldly and completely drought-proof.

Speedwell

Tidy spikes of blue that add vertical punch to the front of the border.

Stokes Aster

Fringed, shaggy-petaled flowers in shades of cornflower blue that bloom for weeks on a tough Southern native.

The President Clematis

Big, rich violet-blue flowers with silvery reverse petals rebloom through the season on a vigorous, reliable plant.

Walker's Low Catmint

Perennial Plant of the Year. Billowy lavender-blue spikes that rebloom hard after a shear.