Delphinium grandiflorum Summer Morning | Siberian Larkspur

Delphinium grandiflorum ‘Summer Morning’, also known as Siberian Larkspur, is a beautiful compact perennial Delphinium, growing to approximately 35 cm tall.

Unlike the tall Delphinium varieties commonly grown for dramatic flower spikes, Summer Morning has a low, naturally compact habit, making it an excellent choice for flower beds, borders, pots and mixed containers.

The plant develops delicate flowers above finely divided green foliage, creating a soft and natural appearance. Its smaller size makes it particularly useful for small gardens and container planting.

Summer Morning is a FastraX perennial, which means it can flower in the first year from seed without requiring vernalization or a cold period.

Plant Information

• Botanical name: Delphinium grandiflorum
• Variety: Summer Morning
• Common name: Siberian Larkspur
• Plant type: Hardy perennial
• Height: Approx. 35 cm
• Position: Full sun to partial shade
• Flowering: First year from seed
• Vernalization: Not required
• Crop time: Approx. 16–20 weeks
• Hardiness zones: 3b–7b
• Seed form: Raw seed
• Uses: Pots, mixed containers, borders, flower beds, landscape planting and small cut flower arrangements

A Compact Delphinium for Pots and Borders

Summer Morning grows to only around 35 cm, making it much more compact than traditional tall Delphiniums.

Its naturally neat growth habit makes it particularly suitable for pots and mixed containers, where it can be combined with other flowering and foliage plants.

In the garden, plant it towards the front or middle of a flower border.

It is an excellent choice if you love Delphiniums but need a variety suitable for smaller gardens, containers or lower planting schemes.

Flowers in the First Year

One of the biggest advantages of Summer Morning is that it can flower in the same year it is sown.

It belongs to the FastraX perennial group, meaning that no vernalization or cold treatment is required for first-year flowering.

Under good growing conditions, expect approximately:

16–20 weeks from sowing to flowering.

For the best chance of flowering in the first year, sow early indoors.

When to Sow

Recommended sowing time: December–May.

Earlier sowing gives the plants more time to establish and flower during their first season.

How to Sow

Sow 2–3 seeds per cell or small pot.

Cover the seeds lightly with vermiculite or a thin layer of growing medium.

Keep the growing medium consistently moist during germination, but avoid making it waterlogged.

Germination temperature: 20–22°C
Germination time: Approximately 14–18 days

Once the seedlings appear, provide plenty of light and good air circulation.

Transplanting

Young plants are normally ready for transplanting approximately 6–8 weeks after sowing.

They can be transplanted into 9 cm pots, larger containers or directly into the garden when conditions are suitable.

When using larger containers, several plants can be planted together for a fuller display.

Avoid planting the young plants too deeply.

Growing Conditions

Summer Morning prefers full sun to partial shade and performs best in relatively cool growing conditions.

For young plants, an ideal growing temperature is approximately:

13–16°C

In the garden, choose a bright position with good air circulation.

During very hot weather, some protection from strong afternoon sun can be beneficial, as temperatures above approximately 29°C may reduce flower quality.

Soil

Plant in fertile, well-drained soil.

For seedling production, a growing medium with a pH of 5.8–6.5 is suitable.

The soil should retain enough moisture for healthy growth while allowing excess water to drain freely.

Avoid permanently wet or waterlogged soil.

Watering & Feeding

Keep the soil evenly moist while plants are establishing.

Once established, allow the surface of the soil to dry slightly between waterings.

Summer Morning requires moderate feeding. Use a balanced fertilizer during active growth, but avoid excessive fertilization.

Container-grown plants may need more regular watering and feeding than plants grown directly in the garden.

Perfect for Containers

One of the best uses for Summer Morning is container planting.

Its compact height makes it easy to combine with other plants in larger pots and mixed seasonal arrangements.

Several Summer Morning plants can also be planted together in one larger container to create a fuller display.

Summer Morning in the Garden

Summer Morning is beautiful in perennial borders, cottage gardens and natural-style plantings.

Because it grows to only around 35 cm, it works particularly well towards the front of flower beds.

It is a hardy perennial and can return in following years when planted in suitable, well-drained conditions.

Can Summer Morning Be Used as a Cut Flower?

Yes. Summer Morning can also be used as a small cut flower, although its stems are much shorter than those of traditional tall Delphiniums.

Its delicate flowers are especially attractive in small bouquets, table arrangements and natural garden-style floristry.

For long professional Delphinium stems, taller Delphinium elatum varieties are a better choice.

Why Grow Summer Morning?

Compact 35 cm plants • Flowers in the first year • No vernalization required • Hardy perennial • Ideal for pots and mixed containers • Excellent for borders • Suitable for small gardens • Can also be used for small floral arrangements

Perfect For

Pots • Mixed containers • Flower borders • Perennial beds • Cottage gardens • Small gardens • Landscape planting • Small cut flower arrangements

Delphinium grandiflorum ‘Summer Morning’ is a beautiful choice if you are looking for a compact perennial Delphinium that flowers in its first year from seed and is especially well suited to pots, borders and mixed containers.