Round-headed leek - Allium sphaerocephalon (Care, Characteristics, Flower, Images)

Round-headed leek

Also known as: Round-headed garlic

Round-headed leek (Allium sphaerocephalon) is a perennial found throughout Europe northern Africa and western Asia. The large round "head" that blooms in summer is actually made up of hundreds of small purple flowers. Its popularity among gardeners has resulted in many subspecies and a range of local names.

Scientific classification

Species

Round-headed leek (Allium sphaerocephalon)

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Perennial

Lifespan

10 cm

Spread

Green

Leaf Color

1 cm to 6 cm

Flower Size

Red, Purple, Pink, Brown

Flower Color

Green, Brown, Pink

Stem Color

Deciduous

Leaf type

5 - 38 ℃

Ideal Temperature

Spring, Summer

Growth Season

Images of Round-headed leek

Culture

Garden Use

Round-headed leek is a very showy ornamental species often planted at garden borders and in cottage and coastal gardens. It is known for its showy purple blossoms. Round-headed leek blossoms in late summer and is considered perfect for late season gardens. It is thought to have the most ornamental impact visually when planted in groups of twenty bulbs or more.

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Toxicity

Round-headed leek causes mild toxicity to humans, cats, and dogs due to N-propyl disulfide. In humans, ingestion leads to gastrointestinal discomfort and dizziness. Cats and dogs show symptoms like gastrointestinal upset and lethargy upon consuming any part of the plant. Immediate veterinary care is advised for pets displaying unusual symptoms after contact with round-headed leek.

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Quickly Identify Round-headed leek

Upright stature reaching 30-40 inches (76-102 cm)

Clustered globe-shaped umbel with reddish-purple 1-inch (2.5 cm) flowers

Distinct garlic or onion scent in leaves and flowers

Leaves are round, hollow, smooth, and gray-green

Bulblets occasionally form post-flowering

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Care Guide for Round-headed leek

Every week

Water

Full sun

Sunlight

5 - 38 ℃

Ideal Temperature

Garden Soil

Soil Type

Water: Adapted to moist environments, round-headed leek requires consistent hydration, ideally watered weekly. Indoor humidity should be elevated to reflect its natural habitat. As a bulbous plant, proper watering is essential during its growing season for optimal health and blooming.

Fertilize: Round-headed leek thrives on balanced nutrition, especially high-phosphorus fertilizers during flowering, applied every six weeks. Reduce feeding in dormancy to avoid excess nutrients. Dilute fertilizers for young plants, and always water thoroughly post-application to enhance absorption and prevent root burn.

Pruning: Pruning round-headed leek in early to late spring promotes new growth and maintains shape. Remove faded flowers to enhance vigor and air circulation, reducing disease risks. Avoid heavy pruning to support flowering. Regular upkeep ensures a vibrant garden display, boosting round-headed leek's ornamental appeal.

Propagation: Round-headed leek features striking spherical flower heads on slender stems and is best propagated by division. During dormancy, separate bulb clumps ensuring each has roots, then replant with proper spacing. This careful handling fosters healthy growth and results in vibrant blooms over time.

Repotting: Round-headed leek requires excellent drainage when grown in pots to thrive effectively.

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