Black garlic
Allium nigrum · Amaryllidaceae
📷 W. Bulach · CC BY-SA 4.0
⚠️ Bulbes et feuilles peuvent endommager les globules rouges des chiens et surtout des chats ; le risque dépend de la quantité ingérée, crue ou cuite.
The gardener's calendar
Ideal time to plant black garlic: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Family
- Amaryllidaceae
- Type
- Perennial bulb
- Adult height
- 60–70 cm
- Flowering
- May to July
- Foliage
- Deciduous
- Hardiness
- Excellent (–15 °C)
- Origin
- Mediterranean and Asia Minor
- Growth
- Moderate
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability high.
Expert tips
The key tip
Allium nigrum flowers in May-June-July with beautiful and long-lasting white or purple umbels: plant bulbs in October-November at 15 cm deep, spaced 25 cm apart, in full sun and very well-drained soil.
The common mistake
Planting them too shallow or in heavy soil: bulbs rot before sprouting or flower poorly in the first year.
The pro's trick
Leave the flower heads to dry on the plant (until August-September): they stay decorative for a long time, and seeds self-sow slowly.
Seasonal watch
In dry summer, the plant goes dormant (foliage yellows and disappears July-September): this is normal, don't water it.
Care
Light exposure
Install black garlic in full sun for generous flowering and better aromatic compound content. A location sheltered from wind is appreciated, especially in cold regions. It tolerates partial shade, but with less vigorous growth.
Watering
Once established, black garlic is very drought-tolerant. Water regularly during active growth (autumn and spring), then reduce after flowering. In winter, no watering is necessary. Avoid excess moisture, which could promote bulb rot.
Soil
Prefer well-drained, slightly chalky or neutral soil. Black garlic dreads waterlogging; improve heavy soil by adding sand or gravel. Poor soil works perfectly fine, even if stony.
Fertilizer
Undemanding, black garlic needs only moderate feeding. A balanced fertilizer in spring is enough, or simply a surface mulch of compost. Avoid excess nitrogen, which would weaken the plant.
Pruning and cutting
Remove faded flowers to encourage prolonged flowering, unless you want to harvest seeds. Let the foliage dry naturally after flowering before removing it. Clean the bulbs in autumn to remove dead leaves.
Diseases and pests
Black garlic is naturally robust and rarely affected by diseases. White basal rot can occur in overly moist soil. Check for thrips or nematodes if abnormal decline occurs, but avoid systematic chemical treatments.
Did you know?
Contrary to legend, black garlic does not exist in nature: it is white or pink garlic blackened by oxidation or fermentation. However, Allium nigrum is indeed a distinct botanical species, with pure white or cream flowers emerging from a grayish bulb. Admired since antiquity in Mediterranean gardens, it represents a treasure of wild flora, often overlooked.
Where to buy it
Plant the bulbs in autumn for spring flowering. Pick a plant with healthy foliage and roots that are not exposed. Best time: from September to November.
Add this plant to my garden →Plants from the same family
- RamsonsAllium ursinum
- ChivesAllium schoenoprasum
- Sand leekAllium scorodoprasum
- Elephant garlicAllium ampeloprasum
- OnionAllium cepa
- Belladonna lilyAmaryllis belladonna
Tips generated and checked by Viridia — adapt them to your local climate.