How to Grow and Care for Larkspur

Handle with care: every part of the tall perennial is toxic

Larkspur plants with light blue flower stalks in garden

The Spruce / Autumn Wood

The larkspur flower has an identity issue in that it's the common name for both Delphinium and Consolida ajacis, which are also both in the same buttercup family. As Delphinium, larkspur is considered an herbaceous perennial. But as Consolida ajacis, or true larkspur as it's called, it is considered an annual. However, these closely related cousins look nearly identical, growing delicate little blooms on showy, spikey stems that are adorned by lacy foliage.

As a perennial, larkspur commonly bears purple, blue, or white flowers. Lavender is the next most common color. You will occasionally encounter larkspurs with pink blooms, and other colors exist but are rarer. Larkspur is valued as one of the traditional plants for cottage gardens. Meanwhile, they are useful for drawing butterflies and hummingbirds to the yard. Larkspur is a toxic plant. Take precautions to prevent children and pets from ingesting it.


All parts of a larkspur plant are toxic so take precautions to prevent children and pets from touching or ingesting the flower. Touching the plant can affect the skin with a minor rash, but it is dangerous to eat the plant, especially the flowers and seeds.

Common Name  Larkspur, giant larkspur
Botanical Name Delphinium (sometimes considered Consolida ajacis)
Family Ranunculaceae (buttercup)
Plant Type Perennial (sometimes considered hardy annual)
Mature Size 1-7 ft. depending on type
Sun Exposure Full
Soil Type Moist, well-drained
Soil pH Slightly alkaline
Bloom Time Spring and summer
Flower Color Purple, blue, white, pink, or lavender
Hardiness Zones 2-9 (USDA, depending on type)
Native Areas Northern Hemisphere
Toxicity Toxic to humans and pets

Larkspur Care

Most larkspur plants, however, are considered stately perennials ideal for growing at the back of a flower border. The drawback with these is that you have to stake them. For example, 'Cassius' is one of the tall types of Delphinium. This D. Elatum hybrid definitely needs to be staked. If you prefer low-maintenance landscaping, opt for dwarf types.

Their impressive height (some types reach 7 feet tall) makes them extremely showy specimens. The taller types of larkspur are well worth growing if you do not mind performing a bit of maintenance.

There's no need to do anything with a true larkspur for the winter as some are annuals and the others which are considered delphiniums are short-lived perennials that will die back on their own before the first frost.


Full sun is best for larkspur. The plant needs between 6 and 8 hours of sun daily.


Give them a moist, cool, well-drained soil. The soil can be kept cool and moist by furnishing with mulch.


Water the plants once or twice a week. Give the flowers an inch of water every time you water. If the soil becomes waterlogged, stick to watering the plants once a week.

Temperature and Humidity

Larkspur prefers cooler temperatures, which also triggers blooming. The plant prefers mild summerlike conditions that are not humid, however, seedlings may prefer some humidity.


Fertilize your larkspur plants every spring with compost.

Types of Larkspur

When most gardeners think of larkspur, they think of a plant with blue flowers. As you can see, there are many choices in blue larkspurs. They differ in terms of hardiness, size, and the precise quality of the blue flower color. Here are 10 popular larkspur types:

  • Black Knight Larkspur (Delphinium 'Black Knight'): Deep purple blooms, 4 to 6 feet tall
  • Galahad Larkspur (Delphinium 'Galahad'); Snow-white petals, 4 to 6 feet tall
  • Astolat Larkspur (Delphinium Astolat Group): Pink to lavender pink petals, 4 to 6 feet tall
  • Guardian Lavender Larkspur (Delphinium elatum 'Guardian Lavender'): Lavender blossoms, 2 to 4 feet tall
  • Dwarf Larkspur (Delphinium tricorne): Deep violet blue flowers, dwarf, 1 to 3 feet tall
  • Blue Mirror Larkspur (Delphinium 'Blue Mirror'): Blue and lavender blossoms, dwarf, 2 feet tall
  • Cassius Larkspur (Delphinium 'Cassius'): Blue blooms with black centers, 6 to 7 feet tall
  • Summer Skies Larkspur (Delphinium 'Summer Skies'): Pale blue flowers, 5 feet tall
  • Golden Larkspur (Delphinium luteum): Very rare yellow blooms, 2 feet tall, grows only in California
  • Red Lark Larkspur (Delphinium 'Red Lark'): Rare red blooms, 2 to 3 feet tall
Delphinium with lavender flowers.
Guardian Lavender Larkspur (Delphinium 'Guardian Lavender')

Horst Sollinger / Getty Images

Closeup of deep blue larkspur.
Blue Mirror Larkspur (Delphinium 'Blue Mirror')

Jackie Bale / Getty Images

Yellow larkspur flower closeup.
Golden Larkspur (Delphinium Luteum)

Hal Beral / Getty Images


Prune off the flower stalks after the plants are done blooming in late summer or early fall.

After the first hard freeze of the autumn, cut the plants down to ground level and remove the vegetation from the area. Because larkspur plants are highly susceptible to diseases, cleanliness in the garden is crucial for them, so do not let the old vegetation lie around all winter. Likewise, do not compost any plant material that you suspect has been infected with any disease.

Propagating Larkspur

If you would like to clone a larkspur plant, you can propagate it with a cutting. Cuttings work best with perennial larkspur. Take these steps in the spring, or in the summer after the plant's first flowering, when it's best to take cuttings:

  1. Look for larkspur shoots in your garden. Take a sharp, sterile paring knife (easiest to use for cutting shoots), pull away soil from the shoot, and cut a shoot away from the parent plant from the base of the plant.
  2. Dip the cutting in rooting hormone.
  3. Fill small pots or cups with potting medium that is half potting soil and half perlite.
  4. Keep pots in a cool and humid area, such as under a porch or deck, but do not put them in a greenhouse where it's hot. Keep the soil moist, but not soggy.
  5. You should see roots in a month. Repot cuttings into their own containers or in the ground if it's still cool enough.

How to Grow Larkspur From Seed

An easy way to propagate a lot of larkspur is by seed. Here are the steps:

  1. Find seed pods on spent blooms in the fall that were not deadheaded. Open the pods to retrieve seeds.
  2. Cold stratify seeds. There are many ways to do this. You can put seeds into a damp perlite in a closed jar or container. Put the jar in the refrigerator for about a week.
  3. Choose biodegradable seedling pots and fill them with potting mix. Put a couple of seeds in each pot and cover it with a bit of soil.
  4. Water the pots just a tiny bit and do not make the soil soggy.
  5. Germination should occur in a few weeks.
  6. Plant the seedlings in the pots outdoors in a sunny location, but only after the threat of frost is over.

Potting and Repotting Larkspur

Because of its height, larkspur can look good in a container garden as a focal point in the center or on its own as a potted vertical garden. They grow tall and heavy so they do well when potted in containers with wide bottoms. Consider pots of any material that are at least 12 inches wide with multiple drainage holes to keep the all-purpose potting soil from becoming waterlogged. It's unnecessary to add organic matter to the soil for larkspur.


Potted larkspur may survive the winter if you take a few steps. Cut back the stems to the dirt, mulch the top of the container, and wrap it in burlap for extra insulation. The roots will do best when the pot is sheltered from wind and ice, but there's no need to overwinter the pots indoors.

Common Pests & Plant Diseases

Look out for aphids, cutworms, mealybugs, leafminers, and stalk borers. It is handy that larkspurs are groundhog resistant. These pests will nibble them here and there, but the toxic nature of the plants will kill them. So, the damage will not be extensive. Nor do deer and rabbits tend to eat them.

Many types of larkspur are short-lived. This is due, in part, to their susceptibility to diseases such as botrytis blight and crown rot. Powdery mildew can also be a problem. To lessen the likelihood of your plants being infected by such disease, provide adequate spacing, mulch your larkspurs, and keep your garden free of debris.

How to Get Larkspur to Bloom

Larkspur may not provide a scent, but it does offer stunning stalks of colorful, dainty blossoms. Deadheading spent flowers and stalks encourages blooming. Also, use larkspur as cut flowers to urge the plant to use energy for more blooms. Wilted stalks with mostly spent blooms can be removed. To keep the plants happy and flowering, make sure the soil is moist, but not drenched, during the blooming season. Dry soil will stunt the larkspur's ability to bud and flower.

Common Problems With Larkspur

Larkspur needs maintenance and can often present problems. Whether you have perennials or annuals, look for these signs of trouble.

Blackened Leaves

The plant may be infested with a certain type of microscopic cyclamen mite. It's a translucent mite that causes the plant to stop blooming. This type of mite is difficult to control and you may need to call in a professional with the right type of miticide application.

If the stem is split and you see black streaks on the plants, dig it up and dispose of it or else more bacteria and other problems could enter the plants.

Yellowing Leaves

The plant may have crown rot. Look also for white webby material on the crown which indicates crown rot. Yellowing leaves also indicate a viral infection.

Deformed Plant

The plant likely has a virus, such as mosaic. You will need to dispose of the diseased plant.

  • Is larkspur toxic to touch?

    Touching the leaves and seeds of a larkspur plant can cause skin irritation.

  • Do larkspur come back every year?

    If you have delphinium, also called larkspur, you may have a tender perennial that comes back annually, but it is short-lived only for a few seasons. True larkspur is an annual which reseeds, but the same plant will not come back the next season.

  • What month does larkspur bloom?

    Larkspur blooms in the early summer. It can rebloom in late summer and early fall, as well.

  • How do I know if I have delphinium or Consolida ajacis?

    It is tricky because the annuals reseed and may appear to be perennials. Delphinium's hallmarks are spikes packed with dense blooms and often come in shades of blue and white. Consolida ajacis spikes are not as dense with flowers, and the blossoms look a bit more "loose" than the ones on a delphinium's spike. Consolida ajacis comes in many other colors besides blue and white.

Article Sources
The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Delphinium. North Carolina State Extension.

  2. Delphinium. North Carolina State Extension.

  3. Delphinium. North Carolina State Extension.

  4. Delphinium elatumMissouri Botanical Garden.