Larkspur

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.

Warning

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.

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.

Light

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

Soil

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

Water

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.

Fertilizer

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