Agastache ‘Black Adder’ – A Striking, Long-Flowering Pollinator Magnet
Agastache ‘Black Adder’ is a highly ornamental, clump-forming perennial valued for its tall, slender spikes of rich violet-purple flowers and aromatic, anise-scented foliage. Flowering from early summer through to autumn, the dense flower spires rise above soft green leaves, creating strong vertical structure and long-lasting colour. Its nectar-rich blooms make it one of the best plants for pollinators, while its elegant form adds movement and texture to borders and naturalistic planting schemes.
With its long flowering season, strong colour, and wildlife value, ‘Black Adder’ is both beautiful and highly beneficial to the garden ecosystem.
Why Grow Agastache ‘Black Adder’?
Rich Purple Flower Spikes – Tall, elegant blooms from summer to autumn.
Long Flowering Season – Months of continuous colour.
Pollinator Friendly – Highly attractive to bees, butterflies, and beneficial insects.
Aromatic Foliage – Anise-scented leaves add sensory interest.
Drought Tolerant – Hardy and resilient once established.
Height and Spread
Typically grows to 80–100cm (32–40in) in height, with a spread of 40–50cm (16–20in).
Where to Site Your Agastache ‘Black Adder’
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Mixed Borders: Adds height and movement
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Pollinator Gardens: Essential wildlife plant
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Prairie Planting: Ideal for naturalistic schemes
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Contemporary Borders: Strong vertical structure
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Gravel Gardens: Thrives in free-draining soils
How to Grow and Care
Soil – Prefers well-drained soil; dislikes heavy, wet ground.
Light – Full sun for best flowering and compact growth.
Watering – Water during establishment; drought-tolerant once mature.
Maintenance
Deadheading – Encourages continuous flowering.
Pruning – Cut back in spring once new growth appears.
Mulching – Light mulch in winter for crown protection.
Pests & Diseases – Generally pest- and disease-free.
Perfect Plant Combinations
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Perennials: Echinacea, Rudbeckia, Salvia
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Grasses: Stipa, Panicum
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Shrubs: Lavender, Perovskia
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Pollinator Plants: Verbena, Nepeta
Conclusion
Agastache ‘Black Adder’ is a long-flowering, drought-tolerant perennial with rich purple flower spikes and aromatic foliage. Perfect for borders and wildlife gardens, it delivers structure, colour, and outstanding pollinator value with minimal maintenance.
Does the height include the pot?
No, we measure from the top of the pot to the tip of the plant except for some of the instant planted screens, in this case it will be stated in the description
How long does delivery take?
Most orders are delivered in just a few days, Smaller items are often sent with Parcelforce on a next day service, Larger items should allow up to 10 days due to the size of the items they often have to be sent on our own transport.
Where will you leave my plants?
We will leave your order at the front of your property, Parcelforce may
leave your items in a safe place if you let us know, Pallet couriers
will require a flat hard surface to deliver to, no gravel or soil, a
driveway or parking spot would be best. Most importantly Deliveries by
pallet courier will require access for a large truck (bin lorry sized)
to get near the delivery point. Deliveries sent on our own transport may come in a small van or larger truck.
