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BRASSICA oleracea 'Flash'

Image of Brassica oleracea 'Flash' (Acephala Group)

Jessie Keith



Botanical Name

BRASSICA oleracea 'Flash'( Acephala Group)

Plant Common Name

Collard Greens

General Description

A vigorous, fast-growing collard green, 'Flash' produces large, dark green leaves with milky white stems. The plants are slow to bolt and will quickly regrow when cut back. The first tender leaves are ready to harvest after 55 days when planted from seed and are sweetest when gathered in cool weather. In fact, they're sweetest after the first mild frost of fall. Cook them as you would kale or spinach.

As beautiful as they are delicious, kale, collards, flowering cabbage, and the other vegetables in this group derive from Brassica oleracea, a fleshy-leaved short-lived perennial from the coastal areas of western and southern Europe. They are typically grown as annuals.

Plants in this group have open rosettes (rather than closed heads) of large, fleshy, waxy, edible leaves. Ornamental kales and ornamental cabbages bear many-leaved, chrysanthemum-like rosettes on short stems, whereas collards and culinary kales bear leaves individually on long stout stalks. Plants may produce sprays of four-petaled lemon yellow flowers on tall stems in spring or summer. Some cultivars are highly ornamental and may have pink, purple or variegated leaves that are sometimes deeply lobed, ruffled or curly.

These cool weather crops prefer full sun and fertile, organic-rich garden soil with ample drainage. Most are sown in the chill of early spring or in fall several weeks before first frost. Many taste better if harvested after frost. Tender young leaves can often be harvested for salads a month or so after sowing. Leaves typically mature about 2 months after sowing. Tougher and zestier than many other cabbage greens, mature leaves are usually best steamed or sauteed.

These wonderful, variable vegetables are generally easy to grow. Ornamental selections are beautiful in fall gardens and containers. They make ideal companions to asters, pansies and mums in the autumn garden, and violas and spring bulbs in late winter and spring. Tolerant of subfreezing temperatures, they will perish in severe cold. Ornamental cabbages and kales do best in cool weather, otherwise forming leggy relatively drab plants.


  • AHS Heat Zone

    6 - 1

  • USDA Hardiness Zone

    7 - 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


  • Sun Exposure

    Full Sun, Partial Sun

  • Height

    18"-24" / 45.7cm - 61.0cm

  • Width

    12"-18" / 30.5cm - 45.7cm

  • Bloom Time

    Spring, Late Spring, Early Summer

  • Native To

    Europe, Mediterranean, Canary Islands, Northern Africa

Growing Conditions

  • Soil pH

    Acidic, Neutral, Alkaline

  • Soil Drainage

    Well Drained

  • Soil type

    Clay, Loam, Sand

  • Growth Rate


  • Water Requirements

    Average Water

  • Habit


  • Seasonal Interest

    Spring, Summer, Fall, Winter

Ornamental Features

  • Flower Interest


  • Flower Color


  • Fruit Color


  • Foliage Color (Spring)

    Gray Green, Dark Green

  • Foliage Color (Summer)

    Gray Green, Dark Green

  • Foliage Color (Fall)

    Gray Green, Dark Green

  • Foliage Color (Winter)

    Gray Green, Dark Green

  • Fragrant Flowers


  • Fragrant Fruit


  • Fragrant Foliage


  • Bark or Stem Fragrant


  • Flower Petal Number


  • Repeat Bloomer


  • Showy Fruit


  • Edible Fruit


  • Showy Foliage


  • Foliage Texture


  • Foliage Sheen


  • Evergreen


  • Showy Bark


Special Characteristics

  • Usage

    Edible, Herb / Vegetable

  • Sharp or Has Thorns


  • Invasive


  • Attracts


  • Self-Sowing