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How to Plant and Grow Larkspur

How to Plant and Grow Larkspur

Larkspur, the common name for both Delphinium and Consolida ajacis, is a classic cottage garden staple that produces charming cut flowers. With airy stalks of blue, pink, purple, or white blossoms, this plant adds an enchanting, ethereal look to any garden. Blue is a hard-to-find color in the flower world, and since larkspur has it in numerous hues from sky to navy, the plant is highly sought-after. Larkspur is available in single and double varieties, some of which have so many petals that they have a pom-pom-like appearance.

Larkspur's foliage is also quite charming. Light, airy fronds lend a soft, fern-like effect. It also helps the plant blend in the garden, making it an extremely versatile pairing for other annuals and perennials. Consolida ajacis, considered true larkspur, is an annual that's easy to start from seed and will happily reseed in the garden year after year.

Larkspur's leaves, flowers, and seeds are toxic to humans and cats, dogs, and horses. Plant the annual out of reach from children and animals.

Larkspur Overview

Genus Name Consolida ajacis
Common Name Larkspur
Plant Type Annual
Light Part Sun, Sun
Height 1 to 3 feet
Width 6 to 18 inches
Flower Color Blue, Pink, Purple, Red, White
Foliage Color Blue/Green
Season Features Spring Bloom, Summer Bloom
Special Features Cut Flowers, Good for Containers, Low Maintenance
Propagation Seed
Problem Solvers Deer Resistant, Drought Tolerant

Where to Plant Larkspur

Larkspur is an annual that grows in USDA Hardiness Zones 2-11. It does best in sunny garden beds and borders with well-draining soil. The blooms are tall, so place them behind mounding plants and give them some protection from strong winds.

The plant is a wonderful addition to cottage gardens and butterfly gardens, as the winged creatures are attracted to larkspur's delicate blooms. Include larkspur in your cutting garden for an eye-catching spike of flowers in a bouquet.

How and When to Plant Larkspur

Larkspur is an extremely unfussy plant that grows easily from seed. In southern climates, you can sow seeds directly in the ground during fall. In northern climates, sow seeds in early spring. Larkspur are hardy annuals that tolerate the cool spring weather.

Loosen the soil and plant seeds 1/4-inch deep. Cover them, as they need darkness to germinate, but don't firm down the soil. Space seeds about 4 inches apart and thin to 10 to 12 inches apart when seedlings grow.

Larkspur Care Tips

Larkspur produces beautiful blooms and is very easy to care for.

Light

For the best blooms, plant larkspur in full sun. Although plants can handle a small amount of shade, they are likely to flop and require stakes. You can prevent this by sowing larkspur densely near tall neighbors or planting them along a wall or structure.

Soil and Water

When planting larkspur, make sure you choose well-drained soil. Larkspur doesn't like to stay wet for long periods, but it does need consistent moisture. Be sure that plants stay evenly moist, especially when flowering. If they remain too dry for too long, plants can become stunted and have poor bud set.

Temperature and Humidity

Because it's a cool-season annual, larkspur will begin to turn brown and die in the humid summers of the South. Plants can last longer into the summer in the North before the weather gets too warm for them to handle.

Fertilizer

Fertilize larkspur every spring with compost.

Pruning

When larkspur is done blooming in late summer or early fall, the stalks are ready for pruning. Cut your plants down to the ground after the first fall frost and remove pruned foliage from the area to prevent disease.

Potting and Repotting Larkspur

Larkspur looks stunning at the back of a container garden or in a pot on its own. The plant should be grown in a pot at least 12 inches wide. Choose a container with ample drainage holes to maintain well-drained potting mix.

Since larkspur complete its life cycle within a growing season, there's no need to repot it.

Pests and Problems

Larkspur is relatively insect and disease-free, but illnesses like powdery mildew and botrytis blight can be an issue if the plants aren't adequately spaced or too much debris lingers around the crown. Because all parts of the plant are toxic, it is rare for animals to eat it, although some instances of cattle poisoning have occurred.

How to Propagate Larkspur

The best, most prolific way to propagate larkspur is by seed, though it usually reseeds on its own. To propagate the plant yourself, retrieve seeds from the pods on spent blooms during fall. Cold stratify the seeds for about a week. After the stratification period, fill a seedling tray with potting mix, then place a few seeds in each well, covering with soil. Lightly water, avoiding making the soil soggy. Germination will occur a few weeks later, after which you can transplant seedlings outdoors in a sunny area following the final frost.

Types of Larkspur

Larkspur 'Cloudy Skies Mix'

Consolida 'Cloudy Skies Mix' bears blooms in shades of purple, blue, white, and silver on 3-foot-tall plants.

Larkspur 'Imperial Strain Mix'

Consolida 'Imperial Strain Mix' is decorated with stately spikes in shades of pink, rose, blue, purple, or white on strong 4-foot stems.

Larkspur 'Sublime Mix'

Consolida 'Sublime Mix' produces flower-packed spikes in a variety of shades on 4-foot stems.

Larkspur Companion Plants

Cosmos

You can depend on cosmos to fill your garden with color all season long. The simple, daisylike flowers appear in cheery shades on tall stems that are great for cutting. The lacy foliage makes a pretty backdrop for shorter plants. Cosmos is an annual that often self-seeds in the garden, so you may only have to plant it once, though the colors can appear muddy after reseeding.

Snapdragon

Few gardens should be without the charm of snapdragon. If you gently squeeze the sides of the intricately shaped flower, you'll see the jaws of a dragon head snap closed. The blooms come in gorgeous colors, including some with beautiful color variations on each flower. Snapdragon is especially useful because it's a cool-season annual, coming into its own in early spring when the warm-season annuals are just being planted. They're also great for fall color. Snapdragon often self-seeds if not deadheaded.

Marguerite Daisy

The hallmark of Marguerite daisy is that it loves cool weather, blooming best in most areas in spring and fall, though it will continue to bloom through the summer in regions with mild summers. Flowers bloom in pink, white, and purple hues. Often confused with Shasta daisy, Marguerite is more mounded and shrubby.

Garden Plans for Larkspur

Summer Cottage Garden Plan

This eye-catching, summer-blooming cottage garden plan adds plenty of color and texture to your yard. It is comprised of several classic perennials, including larkspur. Other showstoppers include bellflower, lamb's ear, and cranesbill.

Frequently Asked Questions

  • Is larkspur the same as delphinium?

    Larkspur is the common name for both Delphinium and Consolida ajacis, but the latter is considered true larkspur. A very close relative of Consolida ajacis larkspur, delphinium looks almost identical in many aspects, but a few differences set these two plants apart. Delphinium tends to be a perennial species, whereas larkspur is an annual. The foliage of larkspur is finer textured than delphinium. Delphinium flowers are densely born on spikes, while individual blossoms tend to be much larger than larkspur. With those few exceptions, general plant care and maintenance are the same.

  • Does larkspur attract pollinators?

    Larkspur blooms attract bees—especially bumblebees—and hummingbirds. Bees are larkspur's primary pollinators. Butterflies and other insects are attracted to the plant as well, but they aren't as efficient at pollination.

Sources
Better Homes & Gardens is committed to using high-quality, reputable sources—including peer-reviewed studies—to support the facts in our articles. Read about our editorial policies and standards to learn more about how we fact check our content for accuracy.
  1. Delphinium. NC State Extension.

  2. Larkspur. ASPCA.

  3. Larkspur. Colorado State University College of Veterinary Medicine and Biomedical Sciences.

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