Overview
Agastache 'Black Adder' is a bushy perennial in the genus Agastache, part of the Lamiaceae family, with deciduous foliage. Agastache 'Black Adder' grows best in full sun, and tolerates loam soils and neutral pH. Its UK hardiness is rated H6. Suggested uses include cottage and informal garden, gravel garden, mediterranean climate plants, banks and slopes and flower borders and beds.
About
Agastache 'Black Adder' is a cultivar of Agastache in the mint family Lamiaceae, carrying the aromatic, herbaceous character of its genus. Like other Agastache, it produces upright flower spikes of tubular, two-lipped blooms and leafy stems. It flowers from July to October. The plant suits garden situations where long summer–autumn bloom is wanted.
About the genus
Agastache is a genus of aromatic flowering herbaceous perennial plants in the family Lamiaceae. It contains 22 species, mainly native to North America, one species native to eastern Asia. The common names of the species are a variety of fairly ambiguous and confusing "hyssops" and "mints"; as a whole the genus is known as giant hyssops or hummingbird mints.
Wikipedia contributors, "Agastache", CC BY-SA 4.0 — Agastache
In the garden
Agastache 'Black Adder' belongs to the genus Agastache within the family Lamiaceae; the genus comprises aromatic, herbaceous perennials largely native to North America and known for upright spikes of tubular, two-lipped flowers. While individual cultivars vary, members of the genus typically present a vertical, spike-led flowering habit and foliage with toothed, lance-shaped leaves. Treat Agastache 'Black Adder' as you would an aromatic perennial: place where its flowering spikes are visible through the summer and into autumn. Aim for a position that avoids prolonged waterlogging and allows good air movement around the stems; soils that drain freely help prevent crown wetness in cooler, wetter seasons. A light mulch in winter can moderate soil temperatures, and removing spent flower spikes will keep the display tidy and encourage continued production of bloom within the July to October season. Use the cultivar where tall, architectural flower spikes are required — at the back of herbaceous borders, in gravel or Mediterranean-style beds, or in suitably sized containers. Its extended flowering window makes it a practical choice for filling the late-summer to autumn gap in mixed plantings; plan groupings so the vertical spikes are not obscured by neighbouring lower-growing plants.
Growing conditions
Best soil and position for Agastache
- Sunlight
- Full sun
- Soil type
- Loam
- Soil pH
- Neutral
- Soil moisture
- Well-drained
- Aspect
- South-facing
- Exposure
- Exposed
- UK hardiness
- H6
Plant details
Agastache 'Black Adder' size, habit and characteristics
- Plant type
- Perennial
- Habit
- Bushy
- Foliage
- Deciduous
- Suggested uses
- Cottage and informal garden, Gravel garden, Mediterranean climate plants, Banks and slopes, Flower borders and beds
- Fragrance
- Aromatic, licorice-like scent
Care notes
Pruning and caring for Agastache 'Black Adder'
- Pruning
- Cut back in early spring to encourage fresh growth
- Propagation
- Division in spring, Semi-ripe cuttings in late summer
- Pest resistance
- Generally pest-free
- Disease resistance
- Generally disease-free
Frequently asked questions
Where is the best place to plant Agastache 'Black Adder'?
Agastache 'Black Adder' prefers full sun. It suits exposed positions.
What soil does Agastache 'Black Adder' need?
Agastache 'Black Adder' grows best in loam soil. It prefers neutral soil. Aim for soil that stays well-drained.
How do I prune Agastache 'Black Adder'?
Cut back in early spring to encourage fresh growth.
Is Agastache 'Black Adder' hardy in the UK?
Agastache 'Black Adder' has an RHS hardiness rating of H6, meaning it is very hardy, tolerating -20 to -15°C across most of the UK.
How do I propagate Agastache 'Black Adder'?
Division in spring, Semi-ripe cuttings in late summer.
