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Onion

Allium (AL-ee-um)

Family: Amaryllidaceae Native Herbaceous (3-15 ft)

This genus contains approximately 700 species in the amaryllis family (Amaryllidaceae)and is commonly called onions or ornamental onions. It includes the ones we eat for food as garlic, shallots, chives and onions and the ones grown ornamentally in our gardens. Many are native to the northern hemisphere, where they can be found growing in dry, mountainous regions, forests and disturbed areas. Others are native to Europe and Asia. The genus name comes from the Latin word for garlic. Size varies per species, but the average height is one to three feet tall. Most species will do well in full sun to light shade in fertile, loose, well-drained soil. To propagate species that form bulbs, division is easiest from bulb offsets. These should be divided and planted in the spring for the best results. Sowing from seed is also an option, but some seeds may take years to germinate. After flowering, the foliage may look unwell, so the leaves should be cut back to revive the plant’s interest. To protect plants over the winter months, dig and store any non-hardy species. Flowers are produced on erect or pendant scapes and have 6 petal-like sepals in two rows. Leaves vary per species. Some have basal leaves that wither when the plant flowers and others have persistent leaves. Most plants have an onion or garlic odor to the leaves and flowers. Many ornamental onions are edible and are used in the home vegetable garden. Ornamental ones are great for perennial borders, rock gardens, pollinator gardens or as mass planting. Click here to see a calendar of planting schedules, time-to-harvest, and recommended spacing. Pests, Insects, and Other Plant Problems: Overly damp conditions leave ornamental onions prone to fungal issues, including bulb rot, white rot, rust, and mildew. VIDEO created by Andy Pulte for “Landscape Plant Identification, Taxonomy and Morphology,” a plant identification course offered by the Department of Plant Sciences, University of Tennessee.

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 61 attributes.

How it fits the guild

Guild layer 4 - Herbaceous (3-15 ft)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Full plant profile

Growing Conditions
Plant type
Bulb; Edible; Herbaceous Perennial; Poisonous
Life cycle
Bulb
USDA zones
4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
Light
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
High Organic Matter; Loam (Silt); Sand
Soil drainage
Good Drainage
Available space
Less than 12 inches
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 1 ft. 0 in. - 3 ft. 0 in. | Width: 0 ft. 6 in. - 2 ft. 0 in.
Growth rate
Medium
Maintenance
Low
Canopy layer
4 - Herbaceous (3-15 ft)
Form & Appearance
Habit / form
Erect
Texture
Fine
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Rosulate
Leaf shape
Linear
Leaf value
Edible; Fragrant
Hairs present
No
Leaf detail
Green leaves are flat to linear or cyndrical and hollow. A few have broad leaves. Leaves are basal or stem-clasping. Plants smell of garlic or onion. Varies per variety.
Flower color
Gold/Yellow; Pink; Purple/Lavender; Red/Burgundy; White
Flower value
Edible; Fragrant; Long-lasting; Showy
Flower form
Umbel
Flower shape
Bell; Cup; Star; Tubular
Flower size
< 1 inch
Flower detail
Flowers are small, 6-parted sepals, in a cluster at the top of a naked stem. They vary in shape depending on species but can either be tubular, bell, star, or cupped. Their spherical umbels can be shades white, pink, violet, or yellow and are oftentimes have long-lasting interest.
Bloom time
Spring; Summer
Fruit type
Capsule
Fruit detail
The capsule splits longitudinally and contains small round black seeds.
Stem color
Green
Stem detail
Stems are leafless and range from 6"-5' depending on species.
Wildlife & Ecology
Native status
Native
Origin
Northern Hemisphere, North America and Eurasia
Attracts
Bees; Butterflies
Play value
Attractive Flowers; Attracts Pollinators; Colorful; Fragrance; Wildlife Food Source
Food & Medicine
Edible parts
Leaves; Flowers
Fruit type
Capsule

Edibility

Flowers have a mildly bitter flavor and like young leaves can be eaten in small quantities raw in salads and sandwiches or cooked in tea and soups. However, the plant also has poisonous characteristics as noted in the "Poisonous to Humans" section of this record. Toxicity can depend on the age of the person or animal, the age of the plant, the part of the plant ingested, how much is ingested, whether the person or animal has sensitivities or allergies, whether it's eaten raw or cooked, and so forth. Consult with a medical professional for further details.

Landscape Use
Landscape location
Container
Landscape theme
Butterfly Garden; Edible Garden; Pollinator Garden; Rock Garden
Design feature
Border; Mass Planting
Garden tags
#hardy #full sun tolerant #red flowers #white flowers #poisonous #purple flowers #summer bulbs #edible garden #spring interest #butterfly friendly #summer flowers #bulb #ebh-vh #ebh #fragrant leaves #pollinator plant #perennial bulbs #bee friendly #edible landscaping #perennial flowers #herbaceous #showy flowers #rich soils #star shaped flowers #mass planting #yellow flowers #summer interest #pink flowers #fragrant flowers #sandy soils tolerant #loamy soils tolerant #herbaceous perennial #border planting #rock garden #spring flowers #tubular flowers #container plant #landscape plant sleuths course #bell-shaped flowers #perennial #violet flowers #HS304 #weedy #hortcontest #edible #th-touch #th-sowing #wildlife friendly #th-taste #th-smell
Problems & Resistance
Insect problems
Bulb Mites; Insect and Related Pests of Vegetables; Pests of Onion
Problems
Weedy
Resistant to
Deer
Propagation
Division
Poison severity
Low
Poison parts
Bark; Flowers; Fruits; Leaves; Roots; Seeds; Stems
Poison symptoms
If eaten in large quantities symptoms may include nausea, vomiting, and diarrhea.
Toxic principle
Sulfides
Contact dermatitis
No
Toxicity summary
Low severity poison; parts: Bark; Flowers; Fruits; Leaves; Roots; Seeds; Stems

Planted at Hunnicutt

Nobody’s planted this one yet.