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Delphinium Black Knight 3 Litre Pot

A tall perennial with dramatic nearly black-purple flower spikes in early to mid-summer.

Delphinium Black KnightDelphinium Black Knight
Full sun H5 (-15 to -10°C) 1.5-2.5m × 0.5-1m Deciduous Purple Summer Chalk, Loam, Sand South-facing, East-facing, West-facing Pot Grown
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Price:£5.95
SKU: 160422VAT included.
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Delphinium Black Knight
Delphinium Black Knight
Sunlight
Hardiness
H5 (-15 to -10°C)
Mature size
1.5-2.5m tall × 0.5-1m wide
Foliage
Deciduous
Flowers
Soil
Supplied as
Pot Grown

Delphinium ‘Black Knight’ – A Dramatic Dark Blooming Perennial

Delphinium ‘Black Knight’ is a striking perennial renowned for its tall spikes of deep, almost black-purple flowers that bloom in early to mid-summer. Its strong, upright stems and finely divided foliage create architectural interest, while the dramatic, richly coloured blooms add height, drama, and elegance to borders, cottage gardens, and mixed perennial plantings. This long-flowering variety is ideal for gardeners seeking bold contrast and vertical impact in their designs.


Why Grow Delphinium ‘Black Knight’?

Dark, Dramatic Flowers – Tall spikes of nearly black-purple blooms.

Architectural Form – Upright, strong stems add height and structure.

Long Flowering Season – Early to mid-summer colour for extended impact.

Pollinator Friendly – Attracts bees and other beneficial insects.

Versatile Planting – Performs well in borders, cottage gardens, and perennial mixes.


Height and Spread

Typically grows to 120–180cm (4–6ft) in height, with a spread of 45–60cm (18–24in).


Where to Site Your Delphinium ‘Black Knight’

  • Borders: Provides striking vertical and colour impact

  • Cottage Gardens: Naturalistic, romantic planting

  • Mixed Perennial Beds: Adds height and contrast

  • Pollinator-Friendly Gardens: Supports bees and insects

  • Cut Flower Gardens: Excellent for floral arrangements


How to Grow and Care

Soil – Prefers fertile, well-drained soil rich in organic matter.
Light – Full sun for best flowering.
Watering – Keep soil evenly moist, especially during dry spells.


Maintenance

Staking: Strong stems benefit from staking to prevent flopping.
Deadheading: Remove spent flowers to encourage prolonged bloom.
Mulching: Helps retain moisture and enrich the soil.
Pests & Diseases: Generally pest-resistant; monitor for slugs and snails.


Perfect Plant Combinations

  • Perennials: Foxglove, Digitalis, Nepeta

  • Grasses: Miscanthus, Pennisetum for texture contrast

  • Shrubs: Hydrangea, Philadelphus

  • Companion Colours: Whites, soft pinks, and blues for dramatic contrast


Conclusion

Delphinium ‘Black Knight’ is a dramatic, tall perennial with nearly black-purple flower spikes and architectural foliage. Perfect for borders, cottage gardens, and cut flowers, it provides bold vertical impact, long-lasting blooms, and garden drama with minimal fuss.

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