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2L pot shown; pictured in March
2L pot shown; pictured in March
Agastache 'Black Adder'
Agastache 'Black Adder'
Agastache 'Black Adder'
Agastache 'Black Adder'

* Your plant may differ from the images shown depending on the pot size and season.

Giant Hyssop 'Black Adder'

Agastache 'Black Adder'

Agastache 'Black Adder'

£10.95
£10.95
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Agastache 'Black Adder' is a perennial plant valued for its tall spires of deep bluish-violet flowers and dark, moody stems. It attracts plenty of wildlife while in bloom between midsummer and autumn.
Choose a size: 9cm pot

Plant height is measured from the base of the pot to the top of the plant. Heights are approximate and may vary with season.

The most common sized pots we sell from our nursery are 9cm, 17cm (2L), 19cm (3L) and 22.5cm (5L).

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8+ plants

£10.95/ each

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14+ plants

£10.07/ each

Save 8%

28+ plants

£9.64/ each

Save 12%

46+ plants

£9.31/ each

Save 15%

Order before 11PM for delivery by Monday 18th May or sooner. Express delivery also available.

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Key features

Agastache 'Black Adder' (Giant Hyssop 'Black Adder')

Giant hyssop 'Black Adder' is a perennial that brings height and drama to sunny planting schemes. The elegant spikes of bluey-purple flowers are held on erect stems that are almost black in hue. These are beloved of bees and other pollinators, making this an excellent choice for a wildlife-friendly garden.

This variety, like other varieties of giant hyssop, thrives in warm, sunny and sheltered positions with well drained soil. It can be a good choice for gravel gardens, prairie-style borders and other contemporary planting schemes.

The upright and airy form of this plant makes it a good choice for low-maintenance planting schemes that combine ornamental grasses and late-flowering perennials.

  • Attracts pollinators
    Attracts pollinators
  • Prefers sunny positions
    Sun lover
  • Cottage garden plant
    Cottage garden plant

Plant background

Botanical Name: Agastache 'Black Adder' Common Name: Giant Hyssop 'Black Adder' Genus: Agastache
Plant Type: Perennials Native Area: N. America & E. Asia Colour(s): Purple

Characteristics

Eventual Height: ~0.5-1m Eventual Spread: ~0-0.5m Hardiness: H4 (Fully Hardy)
Life Cycle: Deciduous Preferred Sunlight: Full Sun Preferred Soil: Most soil types

Seasonal information

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Planting
Flowering

Note that this is a rough guide only and may vary depending on your exact location in the UK.

Free delivery over £85

Get free delivery straight to your door when you spend £85 or more.

Happy plants guaranteed

Healthy plants delivered to your door in great shape, or your money back.

Grown in the UK

Our plants are grown in the UK to prepare them for the conditions in your garden.