Delphinium 

(dell-fin' ee-um)

Common name: Delphinium

Family: Ranunculaceae, Buttercup

Height x width: 3-8' x 3'

Growth rate, habit: moderate to fast; upright spikes

Foliage: palmately lobed or divided

Flowers: spurred sepals and four petals, usually blue but also red, white, pink, yellow

(photo courtesy Todd Weinmann, ext.nodak.edu)

Hardiness: zones 2 or 3-7

Soil: well-drained, organic

Light: sun

Pests and problems: bacterial leaf spot, crown rot and black leg; fungal crown and stem rots, damping-off, powdery mildew, leaf spots; viruses; aphids, cutworms, borers, leaf miners, beetles, sowbugs, root mealybug, mites, nematodes, slugs

Landscape habit, uses: front to back of borders

Other interest: hollow and brittle stems, short-lived in the South

Other culture: require heavy fertility, staking of tall cultivars; often short-lived (2-3 years)

Propagation: fresh seed or stratify, solid spring basal cuttings

Species:

Belladonna Group(bell-ah-don' ah)--Belladonna Delphinium, zones 3-7, 3-4' x 3', blue shades of single cup-shaped flowers in mid to late-summer, many flower stems at same time, from elatum and grandiflorum crosses

x bellamosum ('Bellamosa')(bell-ah-mo' sah)--Bellamosa Delphinium, light blue, similar to belladonnas

cardinale (car-di-nale')--Scarlet Larkspur, zones 5-9, 4-6' x 3', scarlet red flowers in early summer on loose central spike, native to So. Calif. so prefers dry scrub areas

Elatum Group(ee-laa' tum)--Hybrid Bee Delphinium, zones 3-7, 4-8' x 3', various colors in summer of large and flat flowers on a central raceme, remove central spike after bloom for later rebloom, "bee" refers to center or eye color

grandiflorum (gran-deh-floor' um)--zones 3-7, 1-2' x 1-2', violet to blue or white flowers, loose inflorescence, more rounded shape, good for front of border, grow quickly so often treated as an annual

nudicaule (nude-eh-call')--zones 5-8, 2-3' x 2', red to orange or yellowish flowers in loose stalk in early summer, native to Pacific Northwest in Coast Ranges so prefers dry or rocky site

semibarbatum (semee-bar-baa' tum)--zones 5-8, 2-3' x 2', yellow flowers in early summer, native to dry steppes of NW China so prefers water in spring only, resents hot and damp summers

zalil: semibarbatum
 
 

Cultivars:

Series are listed for Elatum Group hybrids:

Blackmore and Langdon Strain--4-6' tall, from famous British firm of same name

Pacific Hybrids (Round Table Series)--over 4' tall

Mid-Century Hybrids--4-5' tall, stronger stems and more mildew resistance

Giant Imperial Series--over 4' tall, annuals in parentage

Connecticut Yankee Series--3-4' tall, heavily branched similar to belladonna types

Magic Fountains Strain--2 1/2 - 3' tall
 
 
 
Cultivars, other taxa species, series flowers
'Astolat' Pacific Hybrids lavender-pink, black center
'Black Knight' Pacific Hybrids dark purple, almost black
'Blackmore's Blue' Blackmore and Langdon purplish "delphinium" blue
'Blauer Spiegel' (Blue Mirror) grandiflorum deep blue
'Blauer Zwerg' (Blue Dwarf) grandiflorum gentian blue, 10" tall, long bloom
'Blue Bird' Pacific Hybrids clear blue, white center
'Blue Butterfly' grandiflorum gentian blue, 12-15" tall
'Blue Dwarf':'Blauer Zwerg'    
'Blue Fountains' Connecticut Yankee Series blue, white, mauve
'Blue Mirror':'Blaue Spiegel'    
'Blue Spires' Giant Imperial Strain blue
'Blue Springs' -- blue, lavender doubles (separate plants)
'Blue Tit' Blackmore and Langdon violet blue
'Butterball' Blackmore and Langdon creamy white, yellow center
'Cameliard' Pacific Hybrids lavender-blue
'Casa Blanca' Belladonna Group pure white
'Clivenden Beauty' Belladonna Group sky blue
'Crown Jewel' Blackmore and Langdon lavender-blue, black center
'Galahad' Pacific Hybrids white, large, late
'Guinevere' Pacific Hybrids lavender, pink tones
'Ivory Towers' Mid-Century Hybrids white
'King Arthur' Pacific Hybrids dark blue
'Lancelot' Pacific Hybrids lavender, white eye
'Magic Dark Blue' Magic Fountains Strain dark blue, white center
'Magic Heavenly Blue' Magic Fountains Strain sky blue, white center
'Magic Lilac-Rose' Magic Fountains Strain lilac-rose, white center
'Magic White' Magic Fountains Strain pure white
'Moody Blues' Mid-Century Hybrids light blue
'Purple Triumph' Blackmore and Langdon purple
'Rose Future' Mid-Century Hybrids pink
'Strawberry Fair' Blackmore and Langdon rose-pink, white center
'Summer Skies' Pacific Hybrids light blue, white center
'Turkish Delight' Blackmore and Langdon light pink, white center
'Ultra Violet' Mid-Century Hybrids dark blue

('Blue Butterfly' photo courtesy Missouri Botanical Gardens plantfinder)


©Authored by Dr. Leonard Perry, Professor, University of Vermont as part of PSS123 course.

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