How to Grow and Care for Larkspur

Larkspur is a common name for two members of the buttercup family, DelphiniumandConsolida ajacis. These plants commonly bearpurple, blue, or white flowers, and you will occasionally encounter larkspurs withpink blooms.

AsDelphinium,larkspur is considered anherbaceousperennial. But asConsolida ajacis,it is considered an annual. These closely related cousins look nearly identical, growing delicate little blooms on showy, spiked stems that are adorned by lacy foliage.

Larkspur is valued as one of the traditional plants for cottage gardens, and it's useful for drawing butterflies and hummingbirds to the yard. Larkspur is toxic to people and pets.

Larkspur Care

Larkspur plants prefer full sun, moist but well-draining soil, moderate watering, and cooler temperatures. Perennial in a wide range of zones, these flowers are relatively easygoing as long as they're planted in the right conditions.

Planting

In USDA zones 2 through 9, plant larkspur in fall or spring. Choose a spot that gets full sunlight. You can either direct sow seeds or plant transplants. If transplanting, be sure to water in the plant thoroughly.

Light

Full sun is best for larkspur. The plant needs between six and eight hours of sun daily.

Soil

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

Water

Water the plants once or twice a week. Give the flowers an inch of water every time you water. Consider recent rainfall and avoid watering if the plants are already wet.

Temperature and Humidity

Larkspur prefers cooler temperatures, which also triggers blooming. The plant prefers mild summer-like conditions that are not humid, however, seedlings may prefer some humidity. These plants are frost-tolerant and will survive the winter in zones as cold as zone 2.

Fertilizer

Fertilize your larkspur plants every spring with compost. This will be enough nutrients to get them through the growing season.

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.

• 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.
  

Pruning

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.

Larkspur plants are highly susceptible to disease, 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:

1. Look for larkspur shoots in your garden.
2. 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.
3. Dip the cutting inrooting hormone.
4. Plant the cuttings in small pots with half potting soil and half perlite.
5. 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.
6. 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 stratifyseeds. 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. Plant the seeds in pots and cover them lightly with 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 looks good in acontainer gardenas a focal point or on its own. 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.

Common Pests & Plant Diseases

Look out for aphids, cutworms, mealybugs, leafminers, and stalk borers. Larkspur is susceptible 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.

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

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,.

If the stem is split and you see black streaks on the plants, dig it up and dispose of it to avoid the spread to other 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.

From: thespruce