Royal larkspur (Delphinium variegatum)

Also known as: Thorne's royal larkspur

This upright wildflower can grow up to 50 centimeters tall. It features deeply lobed leaves that sometimes overlap, with hairy, elongated petioles. The plant's branched inflorescence can support up to 25 flowers that are typically spaced apart. The flowers are predominantly a vivid deep blue, though some subspecies may exhibit lighter blue or white blooms.

In This Article

Care Tips Water Sunlight Temperature Soil Fertilize Prune Propagation Repotting Toxicity

Attributes of Royal larkspur

Lifespan

Perennial

Plant Type

Herb

Plant Height

30-90 cm (1-3 feet)

Spread

20-30 cm (8-12 inches)

Leaf Color

Green

Flower Size

2.5-5 cm (1-2 inches)

Flower Color

Blue to Violet

Images of Royal larkspur

Quickly Identify Royal larkspur

Delphinium variegatum can be identified by its tall, erect stems, deeply lobed leaves, and vibrant blue to violet flowers with a characteristic spur at the back. The flowers are arranged in an elongated cluster known as a raceme.

Scientific Classification of Royal larkspur

Phylum

Vascular plants

Class

Dicotyledons

Order

Ranunculales

Family

Buttercup

Genus

Larkspurs

Species

Royal larkspur

Planting and Growing of Royal larkspur

Care Difficulty

Hard

Watering Schedule

Every 2 days

Sunlight Requirements

Full sun

Sunshine Duration

4-8 hours

Ideal Temperature

60-75℉

Soil Type

Potting Mix, Peat Mix

Soil pH

6.5-7.5

Fertilizer Type

Balanced

Pruning Season

Spring, Summer

Pruning Area

Branches, Leaves

Pruning Frequency

2 times a year

Repotting Season

Spring

Pot Type

Plastic, Ceramic

How to Water Royal larkspur?

Delphinium variegatum thrives with moderate watering. Ensure the soil is evenly moist but not waterlogged, typically requiring about 250 ml per session. This balance ensures the plant gets sufficient moisture without risk of root rot. Aim for soil that feels like a wrung-out sponge.

What are the symptoms of an underwatered Royal larkspur? ›

What should I do if my Royal larkspur is not getting enough water? ›

What are the symptoms of an overwatered Royal larkspur? ›

How to save an overwatered Royal larkspur? ›

What Are the Sunlight Requirements for Royal larkspur?

Sunlight Requirements: Full sun, Partial sun

Duration of light: 6 to 8 hours

Delphinium variegatum prospers in a range from full to partial sun. This exposure ensures optimal photosynthesis, promoting vigorous growth, strong stems, and an abundance of vibrant blooms.

Optimal Sunlight Duration ›

Solutions for Ideal Lighting ›

Benefits of Ideal Sunlight ›

What Is the Ideal Temperature Range for Royal larkspur?

Ideal Temperature: 60 ~ 75℉

The ideal temperature range for Delphinium variegatum is between 60 and 75 degrees Fahrenheit. Within this range, the plant can undergo optimal growth, maximizing both the health of its foliage and the vibrancy of its blooms. It is important to maintain these conditions, as deviations can lead to suboptimal growth or even harm to the plant.

What Soil is Best for Royal larkspur?

Soil type: Loam, Sandy loam, Sandy soil

Soil PH: 6.5 ~ 7.5

Delphinium variegatum thrives best in well-drained soil to prevent root rot caused by excess moisture. Ensuring proper drainage enhances aeration, supporting healthy root development and overall plant vigor. This plant prefers soil with moderate fertility, which provides essential nutrients without overwhelming the plant. Balanced fertility aids in robust blooming, resulting in healthier and more vibrant flower spikes. Delphinium variegatum requires soil that retains moisture but is not prone to waterlogging. This balance ensures the plant remains hydrated while preventing diseases related to excessive soil wetness.

How to Fertilize Royal larkspur?

Fertilizer type: Balanced

When fertilizing Delphinium variegatum, it's important to provide the right amount to avoid nutrient imbalances. Use a balanced liquid fertilizer diluted to half its strength for monthly applications. For slow-release granular fertilizers, apply according to package instructions, keeping in mind the plant's mature size and growth rate. Typically, 1 tablespoon per plant is sufficient for each application of slow-release granules.

How to Prune Royal larkspur?

Pruning Time: Spring, Autumn

Begin by removing spent blooms to encourage a second flush of flowers. Cut back to the nearest set of healthy leaves. This directs the plant’s energy towards budding new blooms rather than seed production. After deadheading, focus on shaping the plant. Cut back excessive growth to ensure the plant maintains a bushy, compact shape. Bear in mind the natural growth habit of Delphinium variegatum to preserve its ornamental appeal. Post-bloom, prune the plant to the ground to prepare it for winter or induce a fresh growth spurt. This encourages robust flowering the following season and prevents legginess. More About Pruning Techniques→

How to Propagate Royal larkspur plant?

Propagate Time: Spring, Early spring, Late spring

Delphinium seeds should be stratified before planting, which involves chilling them for about two weeks. This process mimics natural winter conditions, enhancing germination rates.

Choose healthy parent plants and take cuttings in early spring. Trim the cuttings just below a node and ensure they are around 4 to 6 inches long for optimal rooting.

Division should be done in early spring. Dig up the mature plant and gently separate the roots into smaller sections. Ensure each section has a healthy portion of roots for successful propagation.

More About Propagating Techniques→

How to Repot Royal larkspur plant?

Repotting frequency: Every 1-2 years

Repotting should be done in early spring before new growth starts. Look for signs like roots growing out of drainage holes or soil compacting at the top. These signals indicate that it’s time for a new pot to provide more space and nutrients.

Select a pot that is one size larger than the current one, with good drainage holes to prevent waterlogging. This will give the roots plenty of space to expand and promote healthy growth, while also reducing the risk of root rot.

Opt for a well-draining mix, such as a combination of peat, pine bark, and perlite. This soil allows air circulation around the roots, retains moisture without becoming waterlogged, ensuring the plant remains healthy and vibrant.

Toxicity

ingestion

WARNING

The judgment on toxicity and danger is for reference only. We DO NOT GUARANTEE any accuracy of such judgment. Therefore, you SHALL NOT rely on such judgment. It is IMPORTANT TO SEEK PROFESSIONAL ADVICE in advance when necessary.