Delphinium

( del - FIN - ee - um )

At-A-Glance Information

This genus of perennials, biennials and annuals includes plants that need full sun in most cases and regular waterings. Their flowers will attract birds to your garden. Flowers can come in shades of red, pink, lavender and purple and leaves are lobed and divided. These plants are native to many areas throughout the Northern Hemisphere and northern Africa. All species make great additions to borders and make dramatic additions to cut flower arrangements. Take care when planting these flowers in the landscape, as all parts of all species are toxic to humans and pets.

Delphinium Species and Varietals

The genus Delphinium includes around 300 species and is a member of the plant family Ranunculaceae. Consolida, once its own distinct genus, is now absorbed into Delphinium. Delphinium growing zones vary depending on the species; for more information, see the descriptions below. ​To find your zone, click here: Zone Map.

​Delphinium ajacis (Consolida ajacis, Consolida ambigua) (Doubtful Knight's Spur, Rocket Larkspur, Garden Larkspur, Giant Larkspur)
​​This species is native to Eurasia and has naturalized in many areas around the world, including North America. It is frequently cultivated as a garden ornamental, and reaches about 3 feet tall when mature. Flowers are present between June and October each year, and are pink-purple. This species grows well in USDA hardiness zones 2-11.

Delphinium andersonii (Anderson's Larkspur)
This wildflower species is native to western North America, where it grows in the Great Basin and amongst the Sierra Nevadas. It thrives in USDA hardiness zones 3a-8b. These erect perennial plants reach a foot and a half tall when in bloom. Flowers are typically a brilliant dark blue, though this varies a bit and sometimes blooms can be seen bicolored, purple-lavender or white.

Delphinium bakeri (Baker's Larkspur)
Endemic to California, this species is both endangered with extinction and federally protected, known from one wild population near Salmon Creek in Sonoma County. Leaves occur towards the top of the plant, and flowers are blue and white. This species is named for botanist Milo Samuel Baker. It grows well in USDA hardiness zones 8a-9b.

Delphinium barbeyi (Subalpine Larkspur, Tall Larkspur, Barbey's Larkspur)
This species is native to Arizona, Colorado, New Mexico, Utah and Wyoming, and reaches up to 5 feet tall when in bloom. Flower inflorescences can hold up to 50 violet to dark purple flowers when plants are in bloom. Subalpine Larkspur is suited for USDA hardiness zones 4-7.

​Delphinium x belladonna (Belladonna Larkspur, Perennial Larkspur)
This hybrid species grows best in USDA hardiness zones 3-7 or Sunset growing zones 1-9 and 14-24. It has a sturdy and busy habit, to 3-4 feet tall and 2 feet wide. Flower clusters are airy, and come in a variety of colors. Cultivars include 'Belladonna' (with light blue flowers), 'Bellamosum' (with dark blue blooms, pictured), 'Casablanca' (with white flowers), and 'Cliveden Beauty' (with deep turquoise blooms).

Delphinium brunonianum (Musk Larkspur, Musk-Scented Larkspur)
​Reaching up to 10 inches tall at maturity, these plants produce cup-shaped purple flowers in June and July. Blooms have a strong, musky fragrance. Musk Larkspur is native to Central Asia, Afghanistan, Pakistan, Tibet, and the Himalayan Mountains. Musk Larkspur grows well in USDA zones 4-8.

Delphinium californicum (California Larkspur, California Coast Larkspur)
Endemic to California's San Francisco Bay area and Central Coast, this species of Larkspur produces a deep root and large inflorescences of up to 50 greenish-white to lavender somewhat tubular flowers. These flowers grow in USDA hardiness zones 7a-9b. 

Delphinium cardinale (Scarlet Larkspur, Cardinal Larkspur)
This native of California grows best in USDA hardiness zones 7-10 or Sunset growing zones 7 and 14-23. It gets 3-6 feet tall and 2 feet wide, with an erect habit. Roots are thick and woody. Flowers have a scarlet calyx and yellow petals with scarlet tips and attract hummingbirds and butterflies. Plants grown from seed will bloom in their first year. 

Delphinium carolinianum (Carolina Larkspur, Prairie Larkspur, Blue Larkspur, Wild Blue Larkspur, Pine Woods Larkspur, Glade Larkspur)
This perennial flowering plant is native to the central and eastern portions of North America, and prefers to grow in prairies and rocky glades. Blue to white flowers bloom in springtime. Carolina Larkspur grows well in USDA hardiness zones 4-9.

Delphinium decorum (Yellow-Tinge Larkspur, Coastal Larkspur, Coast Delphinium)
Native to Oregon's southern coast down through the San Francisco Bay Area, California, this species forms star-shaped blue to deep purple flowers, sometimes with lighter or even whitish-yellow upper petals. Stems can hold between 2 and 20 flowers each. Spurs are thin and long. Coastal Larkspur grows well in USDA hardiness zones 7-9.

Delphinium denudatum (Jadwar, Judwar, Nirbishi, Nirvisha, Nirvisi, Larkspur)
Native to central Asia, this species is important in India as a medicinal plant, used to treat poisonings, diseases, infections, and as an analgesic. It is a wildflower species, and produces blue star-shaped flowers. Jadwar grows well in USDA hardiness zones 6-9.

Delphinium depauperatum (Slim Larkspur, Dwarf Larkspur, Mountain Larkspur, Blue Mountain Larkspur)
This wildflower species is native to North America, and naturally grows in mountain meadows. From short root systems, these plants produce 16-inch (or less) tall flowering stalks of deep blue and white flowers with spurs. Slim Larkspur grows well in USDA hardiness zones 
Delphinium elatum (Candle Delphinium, Candle Larkspur, Alpine Delphinium, Guardian Lavender, Candle Larkspur, Bee Larkspur)
This species grows in USDA hardiness zones 3-7 or Sunset growing zones A1-A3, 1-10 and 14-24. Native to Siberia, this plant reaches between 3 and 6 feet tall and 2 feet wide and has small dark purple flowers. Choice garden ornamental varieties are outlined below:
'Summer Skies'
With light blue flowers.
'Blue Bird'
With medium-blue flowers.
'Blue Jay'
With medium blue to dark blue blooms.
'Galahad'
Clear white flowers with purple centers. 
'Blue Fountains'
To 2-2.5 feet tall.
'Magic Fountains'
Grows up to 2 to 2.5 feet tall.
'Blue Springs'
Gets to 2-2.5 feet tall.
'Centurion'
Grows to 4-5 feet tall and blooms in the first year.

Delphinium exaltatum (Tall Larkspur)
Native to the central and eastern areas of the United States, this species of Delphinium reaches six and a half feet tall when in bloom, and produces an inflorescence of up to 30 blue-purple to lavender or white flowers from July through September. Tall Larkspur grows best in USDA hardiness zones 4-8.

Delphinium glaucum (Sierra Larkspur, Mountain Larkspur, Glaucus Larkspur, Tower Larkspur)
These wildflowers are native to western North America, from Arizona up to Alaska, and prefer to grow in mountains alongside riverbanks or in meadows in USDA hardiness zones 3a-8b. These plants reach up to 10 feet tall when in bloom, and produce purple to dark violet blooms, with lighter-colored upper petals.

Delphinium gracilentum (Pine Forest Larkspur, Slender Larkspur, Greene's Larkspur)
Endemic to California, this species grows throughout the Sierra Nevada mountain ranges, and typically reaches about a foot and a half tall at maturity. These flowers do best in USDA hardiness zones 3a-7b. Flowers are widely spaced in inflorescences, and are blue, though they are occasionally white to pinkish.

​Delphinium grandiflorum (Delphinium chinense) (Chinese Delphinium, Bouquet Delphinium, Siberian Larkspur)
This is a species of short-lived perennials that are commonly treated as annuals or biennials. They grow best in USDA hardiness zones 3-7 or Sunset growing zones A1-A3, 1-10 and 14-24. They have a bushy, branching habit and get to about 1 foot tall and about as wide. Varieties include 'Dwarf Blue Mirror' (1 foot tall with deep blue flowers), 'Tom Thumb' (8 inches tall with blue flowers), and those in the Blue Butterfly group (which grow to 14 inches tall and have deep blue blooms).

Delphinium gypsophilum (Gypsum-Loving Larkspur, Panoche Creek Larkspur, Pinoche Creek Larkspur)
These plants are endemic to California, where it grows in the central mountainous region of the state at lower-elevations. These plants reach about 5 feet tall at maturity, and produce a pale green stem topped with pale blue to chalky white flowers, occasionally with pink hues.

Delphinium hesperium (Western Larkspur, Coastal Larkspur, Foothill Larkspur)
These woodland and grassland loving plants are endemic to California, where they can be found in the northern part of the state. These are considered wildflowers, and reach 1.5-3 feet tall at maturity. Leaves are deeply lobed and prominently veined, and flowers are brilliant blue to purple, sometimes lighter in the upper petals. There are three subspecies of this plant including the Cuyamaca Larkspur and Pale-Flowered Western Larkspur.

Delphinium hutchinsoniae (Hutchinson's Larkspur, Monterey Larkspur)
Endemic to California, this species of wildflower typically reaches about three feet tall when in bloom, and produces an inflorescence with no more than 10 flowers. Flowers are brilliant purple to lavender in color, and often have lighter-colored to white upper petals. This species does well in USDA hardiness zones 3-7.

Delphinium inopinum (Unexpected Larkspur)
This wildflower species is native to the Sierra Nevadas in California, where it grows in open forest habitats. Inflorescences hold up to 25 flowers that are lavender, dark purple, and white. Plants reach up to 3.3 feet tall with 5-foot flowering stems.

Delphinium leucophaeum (White Rock Larkspur, Pale Larkspur)
Endemic to the Willamette Valley in Oregon, this species is considered to be endangered, and produces white flowers with green markings on each petal tip and blue centers. This species grows well in USDA hardiness zones 7 and 8.

Delphinium luteum (Yellow Larkspur, Golden Larkspur)
This critically endangered (200 individuals as of 2005) species is native to Marin and Sonoma Counties in California. Plants produce unique yellow flowers that are more elongated than those of other species. These plants grow on rocky, foggy hillsides with great drainage and reach up to between 8 and 22 inches tall when mature and in bloom.

​Delphinium nudicaule (Scarlet Larkspur, Canyon Larkspur, Red Larkspur, Orange Larkspur, Canyon Delphinium, Christmas-Horns)
This species grows best in USDA hardiness zones 6-10 or Suset growing zones 5-7 and 14-17 and is native to Northern California and southwestern Oregon. It forms a slender, upright plant that reaches 1-3 feet tall and a little less than one foot wide at maturity. Sparse red blooms; this plant needs sun or partial shade and is best in woodland plantings.

​Delphinium nuttallianum (Two-Lobe Larkspur, Upland Larkspur, Common Larkspur, Nuttall's Larkspur)
These plants are native to western North America, from Canada down through California. They prefer to grow in mountain meadows and sagebrush steppe landscapes, and produces blue-purple to white flowers. Upland Larkspur grows well in USDA hardiness zones 3a-8b.

Delphinium parishii (Desert Larkspur)
This species, as its common name suggests, is a desert-dwelling wildflower that is native to the Mojave Desert in the southwestern United States and northern Mexico. Flowers range from light blue to purple and bloom between April and June each year. This species of Delphinium grows well in USDA hardiness zones 8a-10b.

Delphinium pavonaceum (Delphinium x pavonaceum) (Peacock Delphinium, Peacock Larkspur)
Endemic to the Willamette Valley in Oregon, this wildflower species reaches just under 40 inches tall at maturity, and produces beautiful inflorescences of white flowers with dark purple centers. Flowers bloom from April through June each year. These plants grow well in USDA hardiness zones 6-8.

Delphinium peregrinum (Violet Larkspur)
This species is native to the Mediterranean region, and blooms between April and August. Flowers are typically deep purple to lavender in color, and their shape is reminiscent of a scorpion, with long spurs that curve upwards. These plants do well in heavier soils. This species grows well in USDA hardiness zones 3-7.

Delphinium purpusii (Kern County Larkspur, Rose-Flowered Larkspur)
Endemic California's Tulare and Kern counties, this species of wildflower reaches between 1 and 3 feet tall when in bloom. Flowers in this species are rose-colored and form in inflorescences of up to 20 blooms per flower stalk. This species is considered rare. Kern County Larkspur does well in USDA hardiness zones 7a-9b.

​Delphinium regalis (Consolida regalis, Dephinium consolida) (Forking Larkspur, Rocket-Larkspur, Field Larkspur)
This species, native to western Asia and Europe, typically grows on sandy or chalky soils. It is found in roadside ditches or other disturbed grounds, and reaches up to between 12 and 31 inches tall when mature and in bloom. This species grows well in USDA hardiness zones 3-9.

Delphinium recurvatum (Byron Larkspur, Recurved Larkspur, Valley Larkspur)
Native to California's central valley, this species of perennial wildflower is considered endangered due to development activities. These plants reach a maximum of about a foot and a half tall, and produce blue flowers that have lower darker petals. Sepals are typically curved back, hence the specific epithet recurvatum.

Delphinium tricorne (Dwarf Larkspur, Spring Larkspur, Rock Larkspur)
This species of Larkspur is native to the central and eastern areas of the United States, and produces greyish-green foliage. Flowers are typically white, blue, purple, or a combination of those colors. Blooms are held in clusters of between 6 and 12. The species grows well in USDA hardiness zones 4-7.

Delphinium trolliifolium (Poison Delphinium, Cow Poison, Columbian Larkspur)
Native to Washington, Oregon, and California, this widespread wildflower species reaches just over three feet tall when in bloom, and produces green foliage. Flowers are typically deep to brilliant blue, with white to light-blue upper petals. These flowers thrive in USDA hardiness zones 6b-9b.

Delphinium uliginosum (Swamp Larkspur, Bog Larkspur)
Endemic to California's Inner North Coast Ranges, this species prefers to grow in moist environments, and has fan-shaped leaves. Flowers are typically deep blue-purple, and bloom in spring and summertime in their native range.

Delphinium variegatum (Royal Larkspur)
Endemic to valley and coastal woodlands and grassy areas in California, this wildflower species usually reaches between 1.5 and 2 feet tall when in bloom. Flowers are typically bright blue, and sometimes have lighter colored to white upper petals. This species is hardy in USDA zones 8b-10b.

Delphinium viridescens (Wenatchee Larkspur)
​This species is native to Washington state on the west coast of the United States, and is a unique Larkspur. Flowers produced are dusky purple and green, and bloom in spring and summertime in the plants' native range.
Delphinium spp. Hybrids (Hybrid Delphinium, Hybrid Larkspur)
There are many different cultivars that have been developed over time, which can be hybrids of the species listed above. Some of the most popular cultivars are listed below:
'Atholl'
'Blue Dawn'
'Blue Nile'
'Bruce'
'Cherub'
'Conspicuous'
'Elisabeth Sahin'
'Fenella'
'Jill Curley'​
'Lucia Sahin'
'Margaret'
'Michael Ayres'
'Min'
'Our Deb'
'Raymond Lister'​
'Rosemary Brock'
'Rosy Future'
'Spindrift'
'Sungleam'
'Sweethearts'

Caring for Delphinium

Delphiniums are easy to grow from seed, though they can also be purchased as nursery specimens. Delphiniums grown from seed may not flower in the first year. They should be planted in a spot in the garden that receives full sun (ideally, between 6 and 8 hours of direct sun each day). They require rich, porous soil that is well-draining, with a pH of between 6.5 and 7.5. If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Delphiniums can either be grown in-ground or in containers on patios or walkways. Ensure that soil is well-draining, and that there are adequate holes in the bases of pots to ensure that standing water is not allowed to build up around roots. Choose a spot in the garden that is somewhat sheltered; these plants are tall, and will not do well in areas with winds that can knock them over or damage foliage or flowers. Do not overcrowd when planting. Apply a thick layer of mulch around the base of plantings to increase soil moisture retention, maintain soil temperatures, and suppress weed growth.

Water newly planted Delphiniums regularly as they establish a strong root system. At maturity, they prefer to have somewhat moist soil at all times, especially during their active growth and flowering seasons (spring and summertime). If growing Delphiniums from seed, pinch them back when they reach about 3 inches tall, thinning plants to have two or three main shoots. After plants mature and flower, spent blooming stalks can be removed to neaten their appearance. If planning on collecting seeds, make sure to leave some spent flower spikes on the plant so that seed pods can mature. In fall, after the entire plant wilts, cut it back to the ground. Each year in springtime, apply a 2-inch layer of organic compost around the planting area to improve soil structure, drainage, and nutrient load. Continue with compost applications (1 inch around the base of plants) once a month after flowering begins to best support plants while they are in their active growing and blooming stages.

Propagation

Delphiniums are best propagated by seed. To propagate your Delphinium flowers, follow the instructions below:

Propagating Delphinium by Seed
  1. Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
  2. Harvest your seeds. The seed pods will drop all of their petals and then turn brownish when they are mature. Cut off the pod from the plant and allow it to continue to dry in a cool, dark place. Once they are fully dried out, collect the seeds from inside. Make sure to lay seeds out to dry before attempting to store them to discourage mold inside the seed container. Fresh seeds will germinate best; seeds that are over a year or two old may not germinate.
  3. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 14-21 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
  4. Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.
Delphinium seed pods remain on flowering stems after petals fade away.
Delphinium seeds are typically dark brown.

Problems and Pests

Delphiniums can be susceptible to developing issues with the following pests and diseases in landscapes:
  • Snails and Slugs
  • Aphids
  • Cyclamen Mites
  • Bacterial Leaf Spot
  • Botrytis Blight
  • Powdery Mildew
  • Seedling Rot
For more information on these issues, including how to treat and prevent them, consult the following pages:

Gallery

Delphiniums are knockout flowers when in bloom.
Planting many different colors of Delphiniums in a bed creates a spring multicolored display.
Delphiniums and Dahlias - a perfect pairing.
Delphiniums pair well with many styles of landscapes, including formal (seen above), cottage, pollinator, informal, and Mediterranean.
Delphinium are popular cut flowers; white and blue-purple Delphiniums are paired with Eucalyptus and Asiatic Lily in this bouquet.
This mixed bed features Australian Tree Fern, Kniphofia, Gerber Daisies, Delphinium, Astilbe, Brunnera, Salvia, Coneflower, Black Lace Elderberry, Floss Flower, and Chinese Woolflower.
Hummingbirds and bees love Delphinium flowers.
This mixed garden bed features variously colored Delphiniums that tower over other plantings.
Delphiniums sometimes will need to be staked, especially taller varieties, to prevent them from flopping.

Videos

Learn about these popular garden ornamentals.
How to plant and care for Delphiniums.
How to grow Delphinium from seed.
Delphinium growing quick tips.

Resources

Delphinium Growing Guide
How to Plant, Grow, and Care for Delphiniums
Growing Delphiniums: How to Grow and Care for Perennial Delphinium
Common Annual Delphinium Problems
Wikipedia: Delphinium
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Page 283, Delphinium