GARDENS BY THE BAY
BLUE PERENNIALS & THEIR COMPANIONS
|The single word "blue" is totally inadequate to describe by itself the colour of a flower. So we use descriptive words to help us understand the exact shades we mean. There are many light shades including pale blue, powder blue, milky blue, sky blue, cool blue, soft blue, lavender blue and periwinkle blue to name just a few. Then there are the brighter and darker tones including navy blue, deep blue, bright blue, electric blue, rich blue and gentian blue to name a few more. And the more specifically described steel blue, metallic blue, cobalt blue and sapphire blue. There is even peacock blue that is clearly visible in the image below of a neighbour who came for a stroll through our gardens.
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.
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.
in sun with: Aster (Michaelmas Daisy), Aster novi-belgii 'Benary's Composition Mix', Chrysanthemum spp.,
Aconitum: any dark blue form
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
Aconitum: a cool blue shade
with: Monarda didyma (pink or red shades)
Aconitum x bicolor:
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)
Aconitum x bicolor 'Bicolor': Bicolor Monkshood, blue & white
with: Lilium tigrinum (synonym Lilium lancifolium)
with: Asiatic lilies (warm reds, yellows and oranges)
Aconitum carmichaelii: Azure Monkshood
Aconitum henryi 'Spark's Variety': Oxford blue, 3-4', late-blooming
Aconitum napellus: Blue Monkshood, Common Monkshood, deep blue
More information about and partners for Monkshood can be found at the links below.
with: Sanguisorba canadensis, Chrysanthemum, Aster spp., Ornamental Grasses
with: Acanthus mollis
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'
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"
Ajuga: purple-leaved types
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'
Ajuga 'Caitlin's Giant': bright blue flowers, and large, bronze-toned leaves
combined with: Convallaria majalis, Asarum europeum, Astilbe chinensis 'Pumila',
Do you need to know more about Bugleweed and find companions for those in your gardens? Try the links below.
Hosta sieboldiana 'Elegans', Polygonatum odoratum 'Variegatum' & Athyrium nipponicum 'Pictum'
Ajuga in shade
Ajuga with variegated foliage
Ajuga with silver foliage
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.,
with low-growing shrubs: Potentilla sp., Cotoneaster spp
with small, low-growing Ornamental Grasses: Festuca glauca
to shoot up through: low ground cover plants
Allium caeruleum: Blue Garlic, deep blue, 8-32"x4-6"
behind: Stachys byzantina 'Silver Carpet' (a non-flowering form)
beside: Artemisia 'Powis Castle'
There is more information about the Ornamental Onions at the links below, along with ideas for the perfect partners for these beauties.
numerous Allium forms
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)
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.
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
Anchusa azurea: Italian Bugloss, brilliant blue, 2-5' tall
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, 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
There are many more forms of Anemone and their companions to be found at the following links, along with information you may need for growing them well.
pink Anemone forms
Anemones for shade
white Anemone forms
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'
Aster ericoides 'Blue Star': pale blue Heath Aster, 30"
with: salmon-pink Sedum 'Autumn Joy', Artemisia 'Lambrook Silver'
Aster tongolensis 'Wartburg Star': 18", blue with orange centres
with: Buddleia x 'Lochinch' (hybrid with B. fallowiana, lavender flowers/silvery-gray leaves)
Numerous Asters appear on various pages that can be accessed by following the links below. There is different information about the genus on each page as well.
Asters for shade
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
Campanula lactiflora 'White Flower Farm Selection': mid-blue
combined with: Digitalis ambigua, Chrysanthemum parthenium & Phlox 'Miss Lingard' (white)
Campanula poscharskyana: pale blue creeping Bellflower
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
Campanula rotundifolia: Bluebells of Scotland, blue bellflowers
with: white Campanula rotundifolia 'Alba'
Campanulas come in a variety of colours. Follow the links below for partnership ideas and more information on all types of Bellflower.
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
If you want to try Knapweed in colours other than blue, find lots of ideas at the links below.
silver foliage Knapweed
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 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
Delphinium: light blue
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',
Delphinium: deep blue
& 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)
Delphinium 'Belladonna': sky-blue
behind: Achillea x 'Moonshine', Hemerocallis (lemon-yellow)
Delphinium 'Blue Bird' (medium blue)
Delphinium 'Blue Jay' (mid to dark blue)
Delphinium 'Summer Skies' (soft sky blue)
with: Achillea ptarmica 'The Pearl'
combined with: Achillea 'Coronation Gold' & Chrysanthemum x superbum 'Star of Antwerp'
Delphinium 'Blue Butterfly'
Delphinium 'Blue Mirror' (bright blue) see below
Delphinium 'Blue Elf'
combined with: Phlox paniculata (rose-coloured forms) & Monarda (red)
Delphinium 'Blue Mirror': gentian-blue Chinese Delphinium, 24" tall
Note: treat as a biennial, use at border front
If you want to increase your Delphinium collection, try some of the forms available at the following links. Combine them with partners suggested by gardening experts.
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
Echinops 'Taplow Blue': Globe Thistle
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'
You can find more information about this perennial genus at the link below.
silver foliage Globe Thistle
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
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
Geranium 'Johnson's Blue': lavender-blue
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
Geranium pratense 'Mrs. Kendall Clark': soft blue
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
The Geranium genus has a wealth of members of various colours and for various situations, accessed at the links below. Information about growing them well can also be found.
Geraniums for foliage effect
Geraniums for shade
Simply Special Perennials - Hardy Geranium's many forms
FOR MORE BLUE PERENNIALS & THEIR COMPANIONS, FOLLOW THE LINK BELOW.
All of our own Gardens By The Bay pages can be accessed by clicking on the links below.
GARDEN POETRY |
GARDEN POETRY MUSE
GEORGIAN BAY VIEW
BOTANICAL LATIN - BASICS
CORNER GARDEN CONSTRUCTION  |
CORNER GARDEN PLANTING |
EAST GARDEN |
HOSTA GARDEN |
NORTH GARDEN |
BLUE PERENNIALS Aconitum -
Iris - Vinca
BULBS Allium - Hyacinthus |
Narcissus only |
Tulipa only |
BUTTERFLY MAGNETS Anaphalis - Hemerocallis |
Liatris - Veronicastrum
DAYLILIES Spider & Unusual Form
EDGERS Arabis - Iris |
Nepeta - Veronica
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
Dianthus 'Tiny Rubies' |
Geum coccineum |
Kerria japonica |
Paeonia tenuifolia |
Papaver somniferum |
Salvia 'East Friesland'
Veronica 'Sunny Border Blue'
DIVISION - SPRING ONLY |
DIVISION - FALL ONLY |
DIVISION - SPRING OR FALL |
DO NOT DIVIDE
ORNAMENTAL GRASSES |
LOCAL GARDENS |
GARDENING BOOKS |