Growing Guide
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Vegetable (Cool Season) - Onion Family

Also known as potato onion, multiplier onion (root)
Allium cepa var. aggregatum
Alliaceae Family

An easy-to-grow gourmet favorite, these perennial onions produce a cluster of smaller bulbs instead of one large bulb. You can replant small bulbs for next year’s crop.

Site Characteristics
  • full sun
  • part shade

Soil conditions:

  • requires well-drained soil
Well-drained, average fertility, high in organic matter, neutral pH. Optimum pH is 6.2 to 6.8. Requires plentiful, even moisture for good yields.

Hardiness zones:

  • 2 to 9
Plant Traits

Lifecycle: perennial

Usually grown as an annual.

Ease-of-care: moderately difficult

Easy if you have rich well-drained soil and good weed control.

Height: 1 to 2 feet

Potato onions may grow more than 3 feet tall under optimum conditions.

Spread: 0.5 to 1 feet

Foliage color: medium green

Foliage texture: medium

Shape: upright

Special Considerations
  • frost
Special characteristics:
  • not native to North America - Middle East origin
Special uses:
  • edible landscaping
Growing Information
How to plant:

Propagate by seed, division or separation - Divide and replant at harvest, or save bulbs over winter to plant in spring. Plants seldom produce viable seed in temperate regions.

Germination temperature: 45 F to 95 F

Days to emergence: 4 to 5

Seed can be saved 1 year. - Longer if stored properly in cool, dry location.

Maintenance and care:
Can be direct-seeded, grown from transplants started inside, or from sets -- small bulbs grown from seed the previous season.

Choose a weed-free, well-drained location. Raised beds are ideal. Shallots are good for intercropping with other garden plants, especially early-maturing spring greens. Do not plant where other onion family crops have been grown in the past 3 years.

Direct seed inch deep, to 1 inch apart, in rows 10 to 18 inches apart, 2 to 4 weeks before average last frost. This rate will usually produce a single bulb from each plant. To produce clusters of bulbs, increase spacings to 6 to 8 inches.

Plant sets in fall or early- to mid-spring. Break bulbs into individual cloves and plant about 1 inch deep so that tops are just covered, 6 inches apart, rows 12" apart. You can cut large cloves into smaller pieces as long as head has some root on it. Mulch to reduce soil heaving and protect plants.

Shallots have shallow root systems and need consistent moisture and good weed control. (Be careful. Grass and shallot seedlings can be difficult to distinguish.) Water weekly if weather is dry, and mulch to retain moisture and suppress weeds.

Rarely damaged.

Onion maggot - Use floating row covers to prevent infestations


Rarely damaged.
Browse shallot varieties at our Vegetable Varieties for Gardeners website.

French varieties have pinkish brown skin and pinkish purple flesh.

Dutch varieties have orangish yellow skin, and are larger and more strongly flavored than the French varieties.

Potato onions are closely related to shallots, though they lack the gourmet reputation of their close cousins. Most are heirloom varieties with red, white or yellow bulbs.

Some varieties maintain quality in storage longer than others.