Delphinium Black Knight Group
Also known as Delphinium Pacific Giant 'Black Knight', Delphinium Pacific 'Black Knight', Delphinium 'Black Knight'
- Height × spread
- 1.5m × 0.6m
- Position
- Full sun
- Hardiness
- Cold to -15C (RHS H5)
- Flowers
- Summer, Autumn
Availability
Generally available in late Spring & early Summer
Many plants are seasonal. Call 01234 567890 to check current stock.
About this plant
This has flowers coloured a deep blue-violet shade, black-eyed. The flowers are held on slender stems and are so dark-toned that they tend to blend into the background unless placed with care. Even grown in front of green foliage they can lose their form. Position them so that their beauty can be appreciated, and perhaps used to counterpoint light pastel shades. This is summer flowering, but may repeat if deadheaded.
- Flower colour
- Blue, Violet
- Foliage colour
- Green
- Variegated
- No
- Scent
- No
- Shape
- Column
- Height
- 1.5m
- Spread
- 0.6m
- Season of interest
- Summer, Autumn
- Flowers in
- Summer, Autumn
- Evergreen
- Deciduous
- Garden style
- Cottage garden
- Sun or shade
- Likes full sun, tolerates part shade
- Soil type
- Loam (normal)
- Soil pH
- All types
- Drainage
- Well drained soil
- Hardiness
- Cold to -15C (RHS H5)
- Borders & containers
- Borders
- Use for
- Deer resistant, Rabbit resistant, Bee attraction
- Hazards
- Yes, potentially harmful; Humans: Harmful if eaten
AutumnNow
Autumn - mid · Planting
Deadhead to tidy for winter
Tidy the plant to make the garden ready for winter. When the flowering season concludes around mid-autumn, cut off the flowered stems to their base.
Spring
Spring - late · Outdoors
Feed with slow release fertiliser
Apply a general purpose slow release fertiliser, spreading it around the root area of the plant as it is coming into growth. (Or apply a liquid feed at regular intervals throughout the growing season.)
This is a simple way to provide a nutrient boost as a single annual procedure.
Spring-Autumn · Outdoors
Water during dry periods
For plants in the ground, when there has been little or no rain for a period of 7-10 days and the soil is dry, give it a deep watering and repeat weekly until there is a downpour of rain. Check plants in pots more frequently, especially in hot weather.
Spring-Autumn · Planting
Protect from slugs & snails
Protect young plants and new growth from slugs; mature plants can withstand slugs though damage affects their appearance. Apply nematodes in Spring. Or sprinkle organic slug pellets thinly around plants. Barrier methods, eg copper tape, may help.
Summer
Summer · Planting
Trim dead flowers to develop buds
Take off the flower as it fades. Cut the stalk back to the point where there is a side shoot, preferably facing outwards, near the base of the stalk. If the spent flower is removed this bud will then develop.
Summer-Autumn · Planting
Support tall stems
The plant may require support for long stems. Provide an artificial frame which it can grow through, or loosely tie the whole plant. A network of twigs can be woven together to provide a framework through which the plant can grow.
Tall stems can lean or be battered by weather. Support the plant to keep its vertical lines, aiming for a natural appearance which is easy on the eye.