Blue

Penstemon heterophyllus 'Electric Blue'

Foothills beard tongue

Penstemon heterophyllus 'Heavenly Blue'

Foothill penstemon

Penstemon hirsutus var. pygmaeus

Dwarf hairy beard tongue

Perovskia

Russian sage

Perovskia 'Superba'

Russian sage

Perovskia abrotanoides

Russian sage, Caspian perovskia

Perovskia atriplicifolia

Azure sage

Perovskia scrophulariifolia

Russian sage

Petunia 'Blue Wave'

Petunia 'Mirage Series'

Petunia 'Veranda® Azur'

Trailing petunia

Petunia Veranda® Dark Blue = 'KERVERBLU'

Trailing petunia

Phacelia

Scorpion weed, Bluebell

Phacelia campanularia

California bluebell, Scorpion weed, Desert bluebell, Wild Cantebury bell

Phlox bifida 'Ralph Haywood'

Cleft phlox

Phlox divaricata 'Clouds of Perfume'

Timber phlox

Phlox divaricata subsp. laphamii 'Chattahoochee'

Wild sweet William, Wild blue phlox, Woodland phlox

Phlox paniculata 'Blue Dolphin'

Border phlox

Phlox paniculata 'Eventide'

Border phlox, Perennial phlox, Summer phlox, Autumn phlox, Fall phlox

Phlox paniculata 'Franz Schubert'

Border phlox, Perennial phlox, Summer phlox, Autumn phlox, Fall phlox

Phlox paniculata 'Hampton Court'

Border phlox, Perennial phlox, Summer phlox, Autumn phlox, Fall phlox

Phlox paniculata 'Le Mahdi'

Border phlox, Summer phlox

Phlox subulata 'Emerald Cushion Blue'

Moss phlox, Mountain phlox, Moss pink

Phlox subulata 'Oakington Blue Eyes'

Moss phlox, Mountain phlox, Moss pink

Platycodon

Balloon flower, Chinese bellflower, Japanese balloon flower

Polemonium 'Heaven Scent'

Jacob's ladder

Polemonium 'Northern Lights'

Jacob's ladder

Polemonium 'Sonia's Bluebell'

Jacob's ladder

Polemonium boreale 'Heavenly Habit'

Jacob's ladder

Polemonium caeruleum

Greek valerian, Charity

Polemonium caeruleum Brise d'Anjou = 'Blanjou'

Greek valerian, Charity

Polemonium reptans 'Stairway to Heaven'

American Greek valerian, Creeping polemonium, Jacob's ladder

Polemonium reptans 'Touch of Class'

American Greek valerian, Creeping polemonium, Jacob's ladder

Polemonium yezoense 'Purple Rain'

Jacob's ladder

Polemonium yezoense Kaleidoscope = 'Dunkal'

Jacob's ladder

Pontederia cordata

Pickerel weed, Wampee

Pontederia cordata var. lancifolia

Pickerel weed, Wampee

Pratia pedunculata

Blue star creeper, Stalked pratia

Pratia pedunculata 'County Park'

Blue star creeper, Stalked pratia

Primula 'Alaska Blue Gem'

Primrose

Primula 'Moonstone'

Primrose

Primula 'Rubens Sky Blue'

Scented primrose

Primula denticulata 'Blue-flowered'

Drumstick primula

Primula marginata

Margined primrose

Prunella grandiflora 'Freelander Blue'

Selfheal

Prunella grandiflora 'Freelander'

Selfheal

Prunella vulgaris

Common self heal

Pulmonaria 'Diana Clare'

Lungwort, Jerusalem cowslip