The onion is a cultivated bulb from the amaryllis family (Amaryllidaceae). One of the earliest vegetables cultivated by humans, onions are thought to originate from central Asia and central Persia; their native origin is unknown. The species epithet cepa is Latin for onion. Onions are cool season crops and should be planted in moist but well-drained fertile loose soils in full sun as soon as the ground can be worked in spring. Plant bulbs about 1/2 to 1 inch deep and 6 inches apart. The bulb will make several offsets during the growing season. Onions are ready to harvest when at least 2/3 of the tops have died down. Dig onions with a garden fork to prevent damage and allow to dry or "cure" for 2-3 weeks before using. Store in mesh bags or crates for good air circulation. Historical accounts, dating back over 5000 years, describe onions as food and medicine in addition to being used in art and in the mummification process. The bulbs and tops are edible raw or cooked. However, the plant also has poisonous characteristics as noted in the "Edibility" section of this record. Onions work best in edible gardens. Onions are resistant to damage by deer and rabbits and can be planted near black walnut trees. Insects, Diseases, and Other Plant Problems: Bulb mites can occur. Bulb rot in too-wet soils can occur. VIDEO Created by Laura Barth for "Vegetables, Herbs, Fruits, and Nuts," a plant identification course developed in partnership with Longwood Gardens.
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 sun (6 or more hours of direct sunlight a day)
Soil texture
High Organic Matter; Loam (Silt); Sand
Soil pH
Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist
Available space
Less than 12 inches; 12 inches-3 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 1 ft. 0 in. - 1 ft. 6 in. | Width: 0 ft. 6 in. - 1 ft. 0 in.
Maintenance
Medium
Canopy layer
4 - Herbaceous (1-3 ft)
Form & Appearance
Habit / form
Arching; Erect
Leaf color
Green
Leaf type
Sheath; Simple
Leaf arrangement
Rosulate
Leaf shape
Linear
Leaf margin
Entire
Leaf value
Edible; Fragrant
Leaf size
> 6 inches long, < 1 inch wide
Hairs present
No
Leaf detail
Long and green with a glaucous surface. Sheaths about 1/4 of the stem
Flower color
White
Flower form
Umbel
Flower shape
Bell; Star
Flower detail
Small clusters of white or pink star or bell-shaped flowers with exerted stamens.
Bloom time
Summer
Fruit type
Capsule
Fruit detail
Flowers wither and convert to bulblets
Stem color
Cream/Tan; Green
Stem detail
Hollow round stems
Wildlife & Ecology
Native status
Non-native
Origin
Central Asia and central Persia
Food & Medicine
Harvest time
Summer
Fruit type
Capsule
Edibility
The bulb and tops are edible raw or cooked. 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 theme
Edible Garden
Design feature
Mass Planting; Small groups
Garden tags
#rabbit resistant #deer resistant #problem for dogs #problem for horses #problem for cats #cool season vegetable #vegetable garden #vegetable #black walnut toxicity tolerant #vhfn-v #vhfn #early childhood #child #children #preschool #early care #easy edibles #hortcontest #dye plant #edible #microgreens #th-touch #th-sowing #th-wildlife #th-taste #th-smell
Problems & Resistance
Insect problems
Bulb Mites; Insect and Related Pests of Vegetables; Pests of Onion
Problems
Poisonous to Humans; Problem for Cats; Problem for Dogs; Problem for Horses
Resistant to
Black Walnut; Deer; Rabbits
Poison severity
Low
Poison symptoms
Vomiting, breakdown of red blood cells (hemolytic anemia, Heinz body anemia), blood in urine, weakness, high heart rate, panting