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Ocimum basilicum var. purpurascens 'Dark Opal'

Image of Ocimum basilicum var. purpurascens 'Dark Opal'

Gerald L. Klingaman

Family

Lamiaceae

Botanical Name

Ocimum basilicum var. purpurascens 'Dark Opal'

Plant Common Name

Dark Opal Basil, Purple Basil

General Description

The purple-leaved basil, ‘Dark Opal,’ was an All-American Selections winner in 1962. Its jewel-toned purple leaves deserve just as much attention as its strong, flavorful leaves, which taste great in salads and make attractive herbed vinegar. In hot weather, ‘Dark Opal’ may loose some of its purple leaf color. Nonetheless, it is a beautiful choice for containers and flower gardens as well as herb and vegetable beds.

For many, basil is the perfect culinary herb. It is a bushy annual, or short-lived perennial, that originates from Africa and Asia. As summer warms up, purple basil produces spikes of two-lipped, pale lavender or purple flowers. After flowering, plants put fewer resources towards foliage production and more towards flowers and seeds. This results in smaller, stronger, more acrid tasting leaves. Flowering also tends to diminish the foliar color of purple-leaved selections, so it is best to pick off buds as they appear to keep plants from blooming.

Satisfyingly easy to grow, basil requires full sun and fertile to average, well-drained soil. Grow it as a spring and summer annual in cooler zones and a year-round perennial in warmer locations. Water regularly for good growth and harvest the leaves often to encourage the continued growth of tender shoots and leaves. Basil is the perfect companion plant for tomatoes, so plant a few at the base of their cages or trellises.

Characteristics

  • AHS Heat Zone

    11 - 1

  • USDA Hardiness Zone

    9 - 11

  • Sunset Zone

    A1, A2, A3, H1, H2, 1a, 1b, 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

    Herb

  • Sun Exposure

    Full Sun

  • Height

    12"-28" / 30.5cm - 71.1cm

  • Width

    10"-24" / 25.4cm - 61.0cm

  • Bloom Time

    Indeterminate

  • Native To

    Middle Africa, Southern Africa, Southern Asia, Southeastern Asia

Growing Conditions

  • Soil pH

    Acidic, Neutral, Alkaline

  • Soil Drainage

    Well Drained

  • Soil type

    Loam, Sand

  • Growth Rate

    Very Fast

  • Water Requirements

    Average Water

  • Habit

    Clump-Forming

  • Seasonal Interest

    Spring, Summer, Fall, Winter

Ornamental Features

  • Flower Interest

    Showy

  • Flower Color

    Purple, Lavender

  • Fruit Color

    Tan

  • Foliage Color (Spring)

    Purple, Dark Green

  • Foliage Color (Summer)

    Purple, Dark Green

  • Foliage Color (Fall)

    Purple, Dark Green

  • Foliage Color (Winter)

    Purple, Dark Green

  • Fragrant Flowers

    Yes

  • Fragrant Fruit

    Yes

  • Fragrant Foliage

    Yes

  • Bark or Stem Fragrant

    Yes

  • Flower Petal Number

    Single

  • Repeat Bloomer

    Yes

  • Showy Fruit

    No

  • Edible Fruit

    No

  • Showy Foliage

    Yes

  • Foliage Texture

    Medium

  • Evergreen

    Yes

  • Showy Bark

    No

Special Characteristics

  • Usage

    Bedding Plant, Container, Edible, Herb / Vegetable, Mixed Border

  • Sharp or Has Thorns

    No

  • Invasive

    No

  • Attracts

    Butterflies

  • Self-Sowing

    Yes