Allium Species, Garden Onion, Edible Onion

Allium cepa

Family: Alliaceae
Genus: Allium (AL-ee-um) (Info)
Species: cepa (KEP-uh) (Info)
Synonym:Allium angolense
Synonym:Allium ascalonicum
Synonym:Cepa esculenta
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Water Requirements:

Average Water Needs; Water regularly; do not overwater

Sun Exposure:

Full Sun

Sun to Partial Shade




Foliage Color:



18-24 in. (45-60 cm)


6-9 in. (15-22 cm)


USDA Zone 3a: to -39.9 C (-40 F)

USDA Zone 3b: to -37.2 C (-35 F)

USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

USDA Zone 10a: to -1.1 C (30 F)

USDA Zone 10b: to 1.7 C (35 F)

Where to Grow:

Unknown - Tell us


Unknown - Tell us

Bloom Color:

Pale Pink

Pale Yellow

White/Near White


Bloom Characteristics:

Unknown - Tell us

Bloom Size:

Unknown - Tell us

Bloom Time:

Mid Summer

Other details:

Unknown - Tell us

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

Patent Information:


Propagation Methods:

By dividing rhizomes, tubers, corms or bulbs (including offsets)

From seed; direct sow outdoors in fall

From seed; winter sow in vented containers, coldframe or unheated greenhouse

From seed; sow indoors before last frost

By tip layering

Seed Collecting:

Bag seedheads to capture ripening seed

Allow seedheads to dry on plants; remove and collect seeds

Properly cleaned, seed can be successfully stored


This plant is said to grow outdoors in the following regions:

Glen Avon, California

Pedley, California

Rubidoux, California

Sunnyslope, California

Brooksville, Florida

Mcdonough, Georgia

Lenoir City, Tennessee

New Caney, Texas

Plano, Texas

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Gardeners' Notes:


On Jan 19, 2010, Rupeee from Riverside, CA (Zone 9b) wrote:

Also called Hill Onion, Mother Onion, and Pregnant Onion.
Produces onions up to 4" in diameter under good conditions, and 3" in diameter under average conditions.
When a small bulb (3/4") is planted, it will usually produce 1 or 2 larger bulbs.
When a large bulb (3 to 4") is planted, it will produce approximately 10 to 12 bulbs per cluster.
Flavorful, yet not strong. The 'Potato' onion has good drought resistance, pink root resistance, and is widely adapted for different growing regions, except Florida and southern Texas.
Especially valued for the keeping quality of the small and medium sized bulbs, which keep 8 to 12 months under good conditions.
We've kept small bulbs up to 18 months under ideal conditions.
Some old-timers grow this... read more


On May 7, 2002, lupinelover from Grove City, OH (Zone 6a) wrote:

Some onion types do not flower; instead they form bulblets on the tops of the leaves which can be used as sets for another crop, or eaten.

Laying over onion leaves before they flower helps to make the bulb grow bigger. Growing onions in the same place for several years also reportedly makes the bulbs grow bigger.

Onion flowers can be eaten; they are more strongly flavored than the bulb.


On Jan 3, 2002, Baa wrote:

The onion is one of the few edible crops almost every country in the world would recognise, it is also thought to be one of the oldest cultivated edible crops

Has long, mid green-blue green, hollow tube, onion scented leaves. All parts of the onion are edible but they are most often grown for their bulb which has a very long list of uses.

Onions prefer an open, well drained, fertile soil in full sun so prepare the bed well during Autumn. Prior to planting apply a general fertiliser (organic or chemical depending on your preference) and rake over. Tread down the raked area and rake again until the tilth is fine and even. Make rows half an inch deep and 9 inches apart.

Sow when the soil is workable for an Autumn crop, late February - early April.... read more