Agastache 'Black Adder' (giant hyssop 'Blackadder') is a member of the Lamiaceae family. This perennial exhibits a bushy growth habit and is characterised by its deciduous foliage. It has a hardiness rating of hardy (average winter [-10 to -5ºc]) and is hardy throughout most of the UK apart from inland valleys, at altitude, and in central/northerly locations. May suffer foliage damage and stem dieback in harsh winters in cold gardens, with plants in pots being more vulnerable. It features a flower fragrance.
When fully mature, Agastache 'Black Adder' can reach an ultimate height of 0.5–1 metres and a spread of 0.1–0.5 metres. For optimal growth, it prefers a south–facing or west–facing aspect and a sheltered position. It thrives best in chalk, loam, or sand soil types and should be placed in full sun.
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Flower
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Foliage
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Fruit
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Stem
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