Walla Walla Sweet Onion Seeds

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Walla Walla Sweet Onion Seeds

Walla Walla Sweet Onion Seeds

$3.95 USD
$3.95 USD
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Packet Size: 400 Seeds

Walla Walla Sweet Onion is a classic long-day heirloom prized for its exceptionally mild, low-acid flavor and impressive bulb size. Originally adapted to northern climates, it performs reliably in garden beds and raised beds where cool conditions support strong growth. These sweet onions are ideal for fresh slicing, salads, and sandwiches, offering a crisp texture and delicate taste gardeners consistently seek.

We ship to the Continental U.S. and Alaska only. We cannot ship to Hawaii, overseas U.S. military bases, or U.S. territories.

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Growing Information

Planting

  • Sow seeds indoors 8–10 weeks before the last expected frost in northern regions.
  • Transplant seedlings outdoors once they are several inches tall and the soil is workable.
  • Choose a location with full sun and loose, well-draining soil for optimal bulb expansion.
  • Space plants about 4–6 inches apart in rows to allow bulbs to size up properly.
  • As a long-day onion, this variety performs best in northern latitudes where daylight hours lengthen in summer.
  • Direct sowing is also possible in early spring, planting seeds shallowly and keeping the seedbed evenly moist during germination.

Maintenance

  • Keep soil consistently moist but not waterlogged to support steady bulb formation.
  • Apply a balanced fertilizer during early growth to encourage strong leaf and bulb development.
  • Weed regularly, as onions compete poorly with weeds for nutrients and space.
  • Plants generally grow to about 12–18 inches tall with a narrow spread of 3–6 inches.
  • Mulching helps regulate soil moisture and temperature, especially in fluctuating spring conditions.

Harvest & Storage

  • Walla Walla Sweet Onions typically reach maturity in about 90–110 days after sowing.
  • Well-grown bulbs can become very large, often reaching up to 2 pounds under optimal conditions.
  • Harvest when tops begin to yellow and fall over naturally, indicating full bulb development.
  • After curing in a dry, well-ventilated area, bulbs can be stored for approximately 2–3 months.
  • For best quality, store in a cool, dry place with good air circulation and use sooner than storage onions due to their high moisture content.