Delphinium
( del - FIN - ee - um )
At-A-Glance InformationThis 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.
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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) (Doubtful Knight's Spur, Rocket 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. |
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. 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. |
Delphinium x belladonna This hybrid species grows best in 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 cardinale (Scarlet Larkspur, Cardinal Larkspur) This native of California grows best in 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. Seeds will bloom in the first year. |
Delphinium elatum (Candle Delphinium, Candle Larkspur, Alpine Delphinium, Guardian Lavender, Candle Larkspur)
This species grows in 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 varieties are outlined below:
This species grows in 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 varieties are outlined below:
Delphinium glaucum (Sierra Larkspur, Mountain Larkspur, Glaucus 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. 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) Endemic to California, this species grows throughout the Sierra Nevada mountain ranges, and typically reaches about a foot and a half tall at maturity. 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 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) 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 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. |
Delphinium nudicaule (Scarlet Larkspur, Canyon Larkspur, Red Larkspur, Orange Larkspur, Canyon Delphinium) This species grows best in zones 5-7 and 14-17 and is native to Northern California and southwestern Oregon. It forms a slender, upright plant that gets 1-3 feet tall and a little less than one foot wide. 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. |
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. |
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. |
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. |
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. |
Delphinium recurvatum (Byron Larkspur, Recurved Larkspur, Valley Larkspur) Native to California's central valley, this species of wildflower is uncommonly seen, considered endangered due to development activities in its native range. 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 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. |
Delphinium spp. Ornamental Cultivars
There are many different cultivars that have been developed over time, which can be hybrids of the species listed above or simply happy genetic 'accidents'. Some of the most popular cultivars are listed below:
There are many different cultivars that have been developed over time, which can be hybrids of the species listed above or simply happy genetic 'accidents'. Some of the most popular cultivars are listed below:
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.
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
Propagating Delphinium by Seed
- 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. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
- 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.
- 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.
- 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.
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
Gallery
Delphiniums pair well with many styles of landscapes, including formal (seen above), cottage, pollinator, informal, and Mediterranean.
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Delphinium are popular cut flowers; white and blue-purple Delphiniums are paired with Eucalyptus and Asiatic Lily in this bouquet.
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This mixed bed features Australian Tree Fern, Kniphofia, Gerber Daisies, Delphinium, Astilbe, Brunnera, Salvia, Coneflower, Black Lace Elderberry, Floss Flower, and Chinese Woolflower.
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Videos
Learn about these popular garden ornamentals.
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How to plant and care for Delphiniums.
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How to grow Delphinium from seed.
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Delphinium growing quick tips.
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Resources
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Page 283, Delphinium
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