In fact, there are very few truly blue flowers. Many described as blue in garden literature have more purple as do some of the plants mentioned below.

* Watch for the animated hummingbird and butterfly with the plants that attract them. *
The deer icon indicates plants that deer are not usually attracted to.

The best time and method to propagate plants can be found on our image-intensive PROPAGATION page.

To help your plants grow their best, check out our FERTILIZATION page.

To create your own plant partnerships based on tried and true color theory, check out our GARDEN COLOR page.

To see if a particular plant is on this page press Ctrl+F, type in the name, then click the Find button.

ACONITUM

The adjective "rich" comes to mind when attempting to describe the colour tones of Monkshood. Mostly blues and purples there is even one yellow form. Whichever you choose, you can't go wrong with the companions suggested below. You must be careful when working with this plant, however. All of its parts are highly poisonous to people and animals alike. Wear gloves if you have any open wounds and wash your hands immediately after working around them. Keep away from children and pets by placing them in the back row of any border, well out from reach.

Aconitum:  Monkshood

in sun with:  Aster (Michaelmas Daisy), Aster novi-belgii 'Benary's Composition Mix', Chrysanthemum spp.,
Anemone x hybrida, Anemone japonica, Anemone tomentosa, Helenium autumnale
with:  Anemone hupehensis 'September Charm'
with:  Aquilegia x hybrida 'Biedermeyer', Aquilegia 'Nora Barlow'
in part shade with:  Hosta, Begonia grandis, Cimicifuga spp.
behind:  pastel-coloured Garden mums
behind:  Monarda 'Cambridge Scarlet' or 'Gardenview Scarlet' & white Shasta daisies
behind:  Monarda (pink forms) & Lilium 'Pink Perfection', all behind Gypsophila 'Rosy Veil'
behind:  Phlox paniculata (white)
with:  Lythrum, Monarda, Gypsophila paniculata
behind:  Lilium(soft yellow), ferns, Thalictrum, Astilbe, Hosta
behind:  Hemerocallis (yellow, peach & light orange)

with:  Hemerocallis (melon-coloured with some red tones) & Phlox paniculata (white)
with:  Helianthus, Hemerocallis fulva, Hemerocallis 'Stella d'Oro'
combined with:  Hemerocallis (tawny-coloured), Phlox paniculata (white) & Achillea filipendulina 'Gold Plate'
with:  Veronicastrum virginicum (a white form)
with:  Boltonia asteroides

with:  Monarda didyma (pink or red shades)

synonym:  Aconitum x cammarum
with:  Eupatorium purpureum, Perovskia atriplicifolia, Helenium autumnale, Aster, Heliopsis helianthoides
with:  Rudbeckia hirta, Physostegia virginiana, Achillea spp., Chelone lyonii, Phlox paniculata (white)

with:  Lilium tigrinum (synonym Lilium lancifolium)
with:  Asiatic lilies (warm reds, yellows and oranges)

with:  Sanguisorba canadensis, Chrysanthemum, Aster spp., Ornamental Grasses
with:  Acanthus mollis

with:  Anemone x hybrida

with:  Acanthus mollis

AGAPANTHUS

Tropical looking African Lily, sometimes called Blue Agapanthus as well as Lily-of-the-Nile, has long been thought of as hardy only to Zone 7 or 8. Anyone familiar with the gardens of Larkwhistle on the Bruce Peninsula in Ontario, Canada in Zone 4 knows otherwise. Mounding sandy soil over the top of their plants in fall is sufficient protection there to ensure the return of these lovelies come spring.

Agapanthus patens:  light blue

synonym:  Agapanthus campanulatus ssp. patens
with:  Achillea filipendulina 'Gold Plate'

AJUGA

Bugleweed thrives as a groundcover or edging plant, usually in partial shade, although it will grow in full sun as long as soil is moist. Lush with small flowers in late spring to early summer, bugle will continue to display attractive spoon-shaped leaves for the rest of the season after bloom is over. Some forms spread much more quickly than others, so choose carefully if you don't want this perennial to spread beyond the boundaries you set.

Ajuga reptans:  Bugleweed, bright blue, 4-10"x12-18"

where:  in dry shade of lawn trees, as edger, groundcover around shrubs
ornamental foliaged types:  as edgings or accents
under:  deciduous shrubs, silver and gold leaved plants
with:  Pachysandra terminalis
beside and or under:  Geranium spp., Euphorbia myrsinites
over:  Crocus (small types) or Narcissus (miniature forms)
drifted with:  Campanula portenschlagiana or Campanula poscharskyana
good foliage contrast in front of:  Carex stricta 'Aurea'

with:  Achillea x 'Moonshine'

combined with:  Convallaria majalis, Asarum europeum, Astilbe chinensis 'Pumila',
Hosta sieboldiana 'Elegans', Polygonatum odoratum 'Variegatum' & Athyrium nipponicum 'Pictum'

ALLIUM

Ornamental Onion, or Flowering Onion, in its myriad forms is a welcome addition to any garden. Small starry flowers grow in clusters, some small, some huge, depending on which species you choose. Plant these bulbs in full sun and generally in well-drained soil for best performance.

Allium:  Flowering Onion

with:  Iris, Hemerocallis, Lavandula spp., Thymus spp., Geranium, Nepeta x faassenii, Dianthus spp.,
Stachys byzantina
with low-growing shrubs:  Potentilla sp., Cotoneaster spp
with small, low-growing Ornamental Grasses:  Festuca glauca
to shoot up through:  low ground cover plants

behind:  Stachys byzantina 'Silver Carpet' (a non-flowering form)
beside:  Artemisia 'Powis Castle'

AMSONIA

Blue Star, or Willow Blue Star, has clusters of pale blue star-shaped flowers that bloom in spring to early summer, usually in full sun to part shade.

Amsonia tabernaemontana:  Willow Blue Star, steel-blue

in front of:  Iris 'Super Ego' & Iris 'Summer Skies'
behind:  Aquilegia x hybrida 'Biedermeyer', Aquilegia 'Nora Barlow'
near:  bold shades of Papaver orientale
with:  Thermopsis caroliniana
combined with:  Paeonia &  Iris sibirica (for co-bloom and good foliage after)

ANCHUSA

Italian Bugloss is one plant that has true blue flowers. Blooming in early summer they will do best in full sun, in evenly moist well-drained soil. This is usually a short-lived perennial.

Anchusa:  Bugloss

behind:  Phlox paniculata, Papaver orientale, Platycodon grandiflorus
beside:  Paeonia, Digitalis
in front of:  Echinops ritro
combined with:  Hemerocallis flava, Iris sibirica 'Fourfold White' & Veronica 'Crater Lake Blue'
to hide foliage behind:  Hemerocallis, Liatris

synonym:  Anchusa italica
where:  amid bright flowers, in masses with flowering shrubs
with:  Chrysanthemum x superbum, Achillea, Papaver
behind:   pink Paeonia or Pyrethrum
behind:  Phlox paniculata 'Mt. Fujiyama' (white)
beside:  Digitalis (tall species)
near:  drift of yellow Iris x germanica, Lysimachia punctata

ANEMONE

Anemone, or Windflower, is a very diverse group of plants with species that shine in darkest shade to brightest sun. There are early spring-blooming forms and those that don't perform until the fall right up until frost. The form below is only one of many with blue flowers.

Anemone blanda:  Grecian Windflower

for partnership ideas follow the link to Shade Perennials & Their Companions

ASTER

The Aster is another perennial with many different forms, some early-blooming, others later-blooming. All have star-shaped flowers and whatever their height, season of bloom, preferred exposure or other requirements, they will provide pleasure over a long period of time.

Aster: blue forms

with:  Pennisetum alopecuroides 'Hameln'

with:  salmon-pink Sedum 'Autumn Joy', Artemisia 'Lambrook Silver'

with:  Buddleia x 'Lochinch' (hybrid with B. fallowiana, lavender flowers/silvery-gray leaves)

CAMPANULA

Bellflowers bloom over a long period of time in many different colours, usually white and shades including purple, but there are blue-flowered ones among them, including the forms listed below.

Campanula carpatica 'China Doll':   azure blue Bellflower

combined with:  Potentilla 'Miss Willmott', Sedum 'Dragon's Blood' & Thymus x citriodorus

combined with:  Digitalis ambigua, Chrysanthemum parthenium & Phlox 'Miss Lingard' (white)

where:  front of borders, rock gardens, hanging baskets, window boxes, in dry shade
with:  Chrysanthemum parthenium (Golden Feverfew), Chrysoganum virginianum
with:  drifts of Ajuga, Hosta, Vinca & other ground covers

with:  white Campanula rotundifolia 'Alba'

CENTAUREA

Perennial Cornflower, sometimes called Perennial Bachelor's Button and Mountain Bluet, grows best in full sun and well-drained soil. Cut back after the first flush of flowers for tidier foliage and repeat bloom in fall.

Centaurea montana:  Perennial Cornflower, rich electric-blue or cobalt blue

with:  Dianthus, Hemerocallis, Lythrum
with:  silver Artemisia, white Phlox paniculata
with grasses:  Helictotrichon
with:  Iris x germanica, Papaver orientale
in front of:  Allium, Chrysanthemum x superbum
combined with:  Centranthus ruber, Centranthus ruber 'Snowcloud' & Nepeta x faassenii

CERATOSTIGMA

Plumbago, Blue Plumbago, Leadwort and Blue Leadwort are all common names for this late-flowering perennial with brilliant blue flowers and red-tinged foliage. A perfect groundcover plant at the front of a perennial border.

Ceratostigma plumbaginoides: Plumbago

where:  under flowering shrubs as groundcover, along walkways, in rock walls, at front of borders
under:  flowering shrubs (as groundcover), bronzed mums, rose and purple Aster, bronze Mums
with:  Garden Mum Dendranthema 'El Toro' (red)
interplanted with spring & fall-blooming bulbs:  Crocus, Lycoris, Colchicum (especially lavender) to hide their dying foliage
with:   Coreopsis verticillata 'Zagreb', Helianthus x multiflorus 'Flore Pleno', Hemerocallis 'Stella d'Oro',
Rudbeckia fulgida var. sullivantii
under:  Prunus cerasifera 'Thundercloud'
combined with:  Eupatorium fistulosum & Artemisia 'Silver King'

DELPHINIUM

Delphinium and Larkspur are available in multiple forms referred to as blue, although most of these are more purple-tinged than blue. There are some, however, that can be safely called blue, including those below. Companion them as recommended for a lovely effect.

Delphinium:  blue forms

with:  Achillea ptarmica 'The Pearl'
with:  Dodecatheon meadia (rose-pink)
with:  Lilium martagon (ivory-coloured)
with:  Filipendula rubra
behind:  Helenium 'Gold Fox'
near:  Rosa (climbing forms)
with:  Chrysanthemum x superbum, Monarda didyma (red)
combined with:  Achillea 'Coronation Gold' & Chrysanthemum x superbum 'Star of Antwerp'
behind:  Gypsophila paniculata, Lilium martagon (ivory) & Monarda didyma (red)

behind:  Lilium regale (or any white form), Achillea 'Salmon Beauty' (salmon-pink) with edging of Stachys 'Silver Carpet',
& near the pale pink climbing rose 'New Dawn'
behind:  Monarda 'Marshall's Delight' (bright and showy hot pink)

with:  Thalictrum aquilegifolium
with:  Lilium 'Peach Butterflies' (a recurved Turkscap Butterfly Lily)

behind:  Achillea x 'Moonshine', Hemerocallis (lemon-yellow)

with:  Achillea ptarmica 'The Pearl'
combined with:  Achillea 'Coronation Gold' & Chrysanthemum x superbum 'Star of Antwerp'

combined with:  Phlox paniculata (rose-coloured forms) & Monarda (red)

Note:  treat as a biennial, use at border front

ECHINOPS

Globe Thistle, with its metallic blue flowers, is an excellent background perennial. Watch for seedlings to increase your collection. It is best to move seedlings when quite small to ensure survival. Foliage is as impressive as the blooms. Try the flowers in fresh or dried arrangements.

Echinops ritro:  Globe Thistle, steel blue, metallic blue

where:  in front of shrubs, in mid to rear border position
generally with:  fine-textured plants to soften their bold foliage
with:  drought-tolerant plants i.e. Papaver orientale, Achillea ( esp. yellow forms), Rudbeckia spp, Nepeta
with:  Ornamental Grasses
with:  Phlox paniculata (for shape contrast))
behind:  Paeonia, Anchusa
beside:  Alcea, Digitalis, Aster
to hem in:  Lythrum
foliage contrast with:  Heuchera sanguinea esp. Bressingham Hybrids i.e. 'Bressingham Blaze'
amid:  (shrubby) Paeonia & (grassy) Hemerocallis
in front of:  tall shrubs
with:  Phlox paniculata (esp. pastel shades), Gypsophila paniculata, Sedum 'Autumn Joy', Helenium, Hemerocallis,
Artemisia lactiflora, Achillea 'Moonshine', Echinacea purpurea
combined with:  Aster 'Purple Dome', Echinacea 'White Swan' & Hemerocallis 'Hyperion'
combined with:  bright yellows of Rudbeckia immediately behind, with purple of Perovskia atriplicifolia behind both
combined with:  Artemisia lactiflora, Helenium 'Moorheim Beauty' & Achillea 'Moonshine'

with:  Achillea 'Coronation Gold'

GENTIANA

The species in the Gentian genus are definitely blue, having given their name to an intense hue called gentian blue. They can be low-growing or upright; all have trumpet- or bottle-shaped flowers that bloom in late summer to fall. Preferring evenly moist, humus-rich soil in full sun or partial shade, many species are rock-garden favourites while others succeed in open woodlands.

For partnership ideas, follow the link to Shade Perennials & Their Companions- 2

GERANIUM

Perennial Geranium, or Cranesbill, has attractive divided foliage and early summer bloom in a variety of colours including blue. Plant it some distance in front of your favourite daylily. It will bloom early after which it needs to be cut back hard. For a short time the foliage will look somewhat unattractive, but it is then that the daylily will be coming into bloom and will therefore dominate the picture. And after the daylily has bloomed, the geranium foliage will act as a screen to hide its declining foliage. A perfect companionship...

Geranium x magnificum:  Showy Geranium, blue-violet

note:  if cut back after bloom this perennial geranium will send up new foliage that remains attractive the rest of the summer
with:  Coreopsis auriculata nana, also known as Mouse-Ear Coreopsis

in front of :  Aruncus dioicus 'Kneifii'
with:  pink and white Rosa, Heuchera 'Palace Purple'
between:  Viola ' Huntercombe Purple' & Aster x thompsonii 'Nanus' (underplanted with Anemone blanda)
with:  Thalictrum 'Thundercloud', Verbascum olympicum
with:  Achillea x 'Moonshine', Alchemilla vulgaris
combined with Aquilegia 'Robin' & Heuchera 'June Bride'
with:  Paeonia lactiflora (pink) & Thalictrum aquilegiafolium

combined with:  Geranium endressii "Wargrave Pink' (a warm salmon-pink) & Geranium himalayense

FOR MORE BLUE PERENNIALS & THEIR COMPANIONS, FOLLOW THE LINK BELOW.

• Iris - Vinca

All of our own Gardens By The Bay pages can be accessed by clicking on the links below.

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EAST GARDEN  |  HOSTA GARDEN  |  NORTH GARDEN  |  WINTER GARDENS

PLANT PARTNERSHIPS

BLUE PERENNIALS    Aconitum - Geranium  |  Iris - Vinca

BULBS    Allium - Hyacinthus  |  Narcissus only  |  Tulipa only  |  Minor Bulbs

BUTTERFLY MAGNETS    Anaphalis - Hemerocallis  |  Liatris - Veronicastrum
DAYLILIES      Spider & Unusual Form

EDGERS    Arabis - Iris  |  Nepeta - Veronica

FOLIAGE PERENNIALS     Alchemilla - Tanacetum

HOSTA    Hosta - all

HUMMINGBIRD-FRIENDLY PERENNIALS    Alcea - Salvia

ORANGE PERENNIALS    Achillea - Tulipa

ORNAMENTAL GRASSES    Acorus - Imperata |  Miscanthus - Spodiopogon

PINK PERENNIALS    Achillea - Lilium  |  Lychnis - Veronica

PURPLE PERENNIALS    Aconitum - Liatris  |  Polemonium - Veronica

RED PERENNIALS    Achillea - Veronica

SHADE PERENNIALS    Aegopodium - Erythronium  |  Ferns - Polemonium  |  Polygonatum - Vinca

SILVER FOLIAGE PERENNIALS    Achillea - Cerastium    |    Cornus - Limonium    |    Lunaria - Veronica

SIMPLY SPECIAL PERENNIALS    Acanthus - Saxifraga

WHITE PERENNIALS    Achillea - Iris  |  Kalimeris - Yucca

YELLOW PERENNIALS    Achillea - Hypericum  |  Inula - Verbascum

VARIEGATED-FOLIAGE PERENNIALS    Acorus - Erythronium  |  Hakonechloa - Lysimachia  |  Miscanthus - Yucca

PLANT PROFILES

Dianthus 'Tiny Rubies'  |  Geranium  |  Geum coccineum  |  Kerria japonica  |  Knautia macedonica

Paeonia tenuifolia  |  Papaver somniferum  |  Rudbeckia  |  Salvia 'East Friesland'

Trollius  |  Veronica 'Sunny Border Blue'

PROPAGATION

DIVISION - SPRING ONLY  |   DIVISION - FALL ONLY  |   DIVISION - SPRING OR FALL  |   DO NOT DIVIDE

FERTILIZATION

BULBS  |   ORNAMENTAL GRASSES  |   PERENNIALS  |   SHRUBS  |   VINES

LINKS

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