Plants that bloom in June in Zone 4 with blue flowers

Bachelor's Button

True cornflower blue that almost no other flower can match. Cottage garden classic that self-sows reliably.

Blue False Indigo

Lupine-like spikes on a native that lives forever. Gets better with age.

Blue Fescue

Steel-blue tufted mound. Perfect edging or rock garden accent.

Blue Flax

Delicate sky-blue flowers open each morning on airy stems over fine foliage.

Blue Oat Grass

Compact clumps of steel-blue blades provide year-round color and texture.

Borage

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

Caesar's Brother Siberian Iris

Tall stems hold rich violet-blue flowers above grassy foliage. The Siberian iris benchmark, blooming earlier and longer than bearded types.

Camassia

Tall spikes of starry flowers rise above strappy foliage in late spring.

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.

Clematis

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

Columbine

Delicate, spurred flowers that dance on wiry stems. Hummingbird favorite.

Culinary Sage

Spiky purple blooms above silver-green aromatic foliage. A kitchen herb that doubles as an ornamental.

Delphinium

Towering spires of true blue. The tallest, most dramatic back-of-border plant.

Endless Summer Hydrangea

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

Forget-me-not

Clouds of tiny sky-blue flowers carpet the ground in spring. Self-sows freely under shrubs and around tulips.

Iris

Elegant sword-leaved perennials with intricate, ruffled blooms.

Japanese Iris

Huge, flat, ruffled blooms up to 10 inches across. Needs consistent moisture, especially during bloom.

Larkspur

Tall spires of spurred flowers in deep blue and purple. The annual cousin of delphinium, easier to grow from seed and just as dramatic.

Lisianthus

Rose-like ruffled blooms with the vase life of a chrysanthemum. The flower farmer's secret weapon for high-end arrangements.

Lupine

Dramatic spikes in every color. Short-lived but self-seeds generously.

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.

Native Spiderwort

Three-petaled flowers in blue-purple open fresh each morning on a tough native that blooms for weeks and seeds freely.

Nigella

Sky-blue flowers wreathed in feathery green bracts give way to ornamental striped seed pods. Self-sows freely once you start.

Pickerelweed

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

Rocky Mountain Columbine

Large blue-and-white spurred flowers bloom in late spring above lacy foliage.

Rocky Mountain Penstemon

Spikes of deep blue tubular flowers rise above glossy evergreen foliage in early summer.

Salvia

Vertical flower spikes that hummingbirds and bees cannot resist.

Speedwell

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

Statice

Stiff papery flower clusters that dry to keep their color for years. A cut-flower farmer staple for wreaths and dried bouquets.

The President Clematis

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

Trumpet Gentian

Intense, almost electric blue trumpet flowers on a low mat. The holy grail of alpine gardeners.

Vinca

Evergreen mat with periwinkle-blue flowers. Tough shade ground cover.

Walker's Low Catmint

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

Wild Blue Phlox

Loose clusters of sky-blue flowers float above woodland floors in spring on a fragrant, mat-forming native.