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AGASTACHE 'Black Adder'

Image of Agastache 'Black Adder'

Jesse Saylor

Family

Lamiaceae

Botanical Name

AGASTACHE 'Black Adder'

Plant Common Name

Black Adder Giant Hyssop, Giant Hyssop

General Description

The hybrid hyssop ‘Black Adder’ is a long-blooming plant that attracts plentiful butterflies and bees to the garden. The tall, bushy, herbaceous perennial produces long spikes of dark purple flower buds that open to a powdery violet-blue. It begins blooming in the heat of midsummer and will continue up until frost if regularly deadheaded. Like most members of the mint family, it has fragrant foliage, which smells of anise when crushed.

Full sun is required for best flowering and good performance. This hyssop can be grown in average to dry garden soil, but a well-draining, fertile, alkaline loam will allow it to reach its best. Beware wet, heavy clay soils as these will cause plants to rot, particularly in wet winter weather. One benefit of ‘Black Adder’ is that it is sterile, so it will not toss seeds and sow itself, like other hyssops. This is an ideal plant for any sunny perennial border or butterfly garden.

Characteristics

  • AHS Heat Zone

    12 - 6

  • USDA Hardiness Zone

    5 - 9

  • Sunset Zone

    2a, 2b, 3a, 3b, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24

  • Plant Type

    Perennial

  • Sun Exposure

    Full Sun

  • Height

    24"-36" / 61.0cm - 91.4cm

  • Width

    20"-26" / 50.8cm - 66.0cm

  • Bloom Time

    Summer, Late Summer, Early Fall, Fall, Late Fall

  • Native To

    Hybrid Origin

Growing Conditions

  • Soil pH

    Neutral, Alkaline

  • Soil Drainage

    Well Drained

  • Soil type

    Loam, Sand

  • Tolerances

    Drought

  • Growth Rate

    Fast

  • Water Requirements

    Drought Tolerant, Average Water

  • Habit

    Clump-Forming

  • Seasonal Interest

    Summer, Fall

Ornamental Features

  • Flower Interest

    Showy

  • Flower Color

    Purple, Blue Violet

  • Fruit Color

    Brown

  • Foliage Color (Spring)

    Green

  • Foliage Color (Summer)

    Green

  • Foliage Color (Fall)

    Green

  • Fragrant Flowers

    Yes

  • Fragrant Fruit

    No

  • Fragrant Foliage

    Yes

  • Bark or Stem Fragrant

    No

  • Flower Petal Number

    Single

  • Repeat Bloomer

    Yes

  • Showy Fruit

    No

  • Edible Fruit

    No

  • Showy Foliage

    No

  • Foliage Texture

    Medium

  • Foliage Sheen

    Matte

  • Evergreen

    No

  • Showy Bark

    No

Special Characteristics

  • Usage

    Bedding Plant, Cutflower, Mixed Border

  • Sharp or Has Thorns

    No

  • Invasive

    No

  • Attracts

    Butterflies

  • Self-Sowing

    No