Sierra Larkspur (Delphinium glaucum)

Also known as: Tower Larkspur, Waxy Pale Larkspur

Osha (*Ligusticum porteri*) is a plant species native to western North America. It has garnered significant attention in phytochemical research. This species thrives in moist mountainous areas, particularly along riverbanks and in meadows.

In This Article

Care Tips Water Sunlight Temperature Soil Fertilize Prune Propagation Repotting Toxicity

Attributes of Sierra Larkspur

Lifespan

Perennial

Plant Type

Herb

Plant Height

91 cm to 1.8 m

Spread

30 cm to 75 cm

Leaf Color

Green

Flower Size

2 cm to 3 cm

Flower Color

Purple

Images of Sierra Larkspur

Quickly Identify Sierra Larkspur

Delphinium glaucum can be identified by its tall, erect habit, deeply lobed leaves, and elongated clusters of blue to purple flowers with a distinctive spur at the back.

Scientific Classification of Sierra Larkspur

Phylum

Vascular plants

Class

Dicotyledons

Order

Ranunculales

Family

Buttercup

Genus

Larkspurs

Species

Sierra Larkspur

Planting and Growing of Sierra Larkspur

Care Difficulty

Hard

Watering Schedule

Every 4 days

Sunlight Requirements

Full sun

Sunshine Duration

4-6 hours

Ideal Temperature

60-70℉

Soil Type

Potting Mix, Peat Mix

Soil pH

6-7

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 Sierra Larkspur?

When watering Delphinium glaucum, the aim is to ensure the soil is consistently moist but not waterlogged. Each watering should allow the water to seep thoroughly through the soil, reaching the roots without leaving standing water. Approximately 500ml per watering is usually sufficient, depending on the size of the plant and pot.

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What Are the Sunlight Requirements for Sierra Larkspur?

Sunlight Requirements: Full sun, Partial sun

Duration of light: 6-8 hours daily

Full sun to partial sun, ensuring 6-8 hours daily exposure supports robust photosynthesis, leading to healthy, lush growth and abundant flowering.

What is the best lighting condition for Delphinium glaucum? ›

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What Is the Ideal Temperature Range for Sierra Larkspur?

Ideal Temperature: 60 ~ 70℉

The ideal temperature range for cultivating Delphinium glaucum is between 60°F and 70°F. This temperature range ensures optimal growth and flowering, providing the necessary environmental conditions for the plant's metabolic processes to function efficiently.

What Soil is Best for Sierra Larkspur?

Soil type: Loam, Sandy loam, Acidic soil

Soil PH: 6 ~ 7

Delphinium glaucum thrives in well-drained loamy soil, which provides the perfect balance of drainage and moisture retention. This type of soil ensures that the plant roots have access to necessary nutrients while avoiding root rot from overwatering. Preferring a soil pH range of 6.0 to 7.0, Delphinium glaucum performs best in environments that are neither too acidic nor overly alkaline. This pH range allows for optimal nutrient uptake and healthy plant growth. Incorporating organic matter into the soil enriches it and boosts the nutrient availability for Delphinium glaucum. This is crucial for supporting the lush foliage and vibrant blooms characteristic of this species.

How to Fertilize Sierra Larkspur?

Fertilizer type: Balanced

For Delphinium glaucum, a moderate amount of fertilizer is recommended. Use approximately half strength of a balanced, water-soluble fertilizer once a month during the growing season. This ensures the plant receives necessary nutrients without risking root burn or nutrient imbalance.

How to Prune Sierra Larkspur?

Pruning Time: Spring, Summer

Prune in early spring before new growth starts to optimize the plant's energy for growth. Summer pruning can be done after flowering to remove spent blooms, which will tidy the plant and possibly prompt a second bloom. Pruning during late autumn is advisable to prepare the plant for winter. This involves cutting back the stems to ground level to protect the plant from frost damage and to prepare it for vigorous growth in the following season. More About Pruning Techniques→

How to Propagate Sierra Larkspur plant?

Propagate Time: Spring, Early spring, Late spring

Begin by filling seed trays with a quality seed-starting mix. Sow the seeds on the surface of the soil and lightly cover with vermiculite. The seeds need light to germinate, so do not bury them deeply.

Select a healthy parent plant and take cuttings from non-flowering shoots about 4-6 inches long. Remove the leaves from the lower half of the cutting before planting it in a well-draining medium.

For division, dig up the parent plant and gently separate the roots into sections. Each section should have at least one good shoot and a portion of the root system before replanting in a prepared bed.

How to Repot Sierra Larkspur plant?

Repotting frequency: Every 2-3 years

Look for signs that Delphinium glaucum needs repotting, such as roots emerging from the drainage holes, slowed growth, or compacted soil. The ideal time to repot is during Spring or Autumn when the plant is actively growing, which allows it to quickly adapt to the new environment.

Select a pot that is one size larger than the current one, with good drainage holes. Adequate drainage ensures that excess water flows away from the roots, preventing root rot and promoting healthier growth.

Opt for well-draining loamy soil, enriched with organic matter. This type of soil retains moisture while allowing excess water to escape, creating a balanced environment that supports robust root development and minimizes the risk of root diseases.

Toxicity of Sierra Larkspur

Is Sierra Larkspur toxic to humans?

Sierra Larkspur poses a significant poisoning risk to humans if ingested. The level of toxicity is severe and can result in fatal outcomes. Every part of the plant is toxic, with its toxicity peaking during its early growth stages. Symptoms stem from alkaloid toxicity and may include vomiting, trembling, convulsions, diarrhea, and difficulty breathing. Individual sensitivity to the plant’s toxins can differ based on a person's age, weight, and overall health. This plant is frequently cultivated in residential areas, increasing the risk for children.

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.

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