Onion Seeds - Red Long of Tropea


Allium cepa

HEIRLOOM. Red Long of Tropea is a well-loved heirloom from the South of Italy that produces elongated, purple-red bulbs with excellent sweet flavor. They are also sometimes called “torpedo” onions because of their distinctive pointed shape. The bulbs are not known for their storage quality and are usually used fresh, though they can keep for up to 6 months in ideal storage conditions. This is an intermediate day variety, meaning it is a good choice for growers throughout much of the US, except for the far South. (35-48° N)

These seeds should be direct-sown in early spring in a location with full sun and well-drained, fertile soil. Bulbs will be ready for harvest in about 90 days.

  • Planting Information
  • How to Grow
  • Saving Seeds


Avg. Seeds/PacketPacket WeightPlanting Season Planting Method
2701 gspring-falldirect seed or transplant
Seed DepthDirect Seed SpacingSoil Temp. RangeDays to Sprout
1/2"1"46-86 ℉7-14 
Mature SpacingSun RequirementFrost ToleranceDays to Harvest
3-6"full sun/ part shade frost tolerant90

Bulbing onions are a hardy, low-maintenance crop that mainly needs plenty of sun, and rich, well-draining soil. Make sure to amend your garden bed with an inch or two of compost before planting.


You can plant bulbing onions indoors 8-10 weeks before your last frost to get a jump on the season, or direct-seed them outdoors in early spring and early fall, for varieties that overwinter well. Most growers choose to start bulbing onions indoors and transplant them out, for the best chance of getting fully sized-up bulbs. Onions do best in cool temperatures, but a little afternoon shade can help them take some summer heat. Most varieties are frost-tolerant, but none will tolerate long periods of below-freezing temperatures, so some type of season extension, such as row cover or a cold frame, is a must for most gardeners who want to overwinter their onions.


To start your onions indoors, sow seeds 1/4" deep and 1/4" apart in trays filled with a quality growing medium. Be extra careful to keep the soil moist but not soggy during germination, and make sure the seedlings get good air circulation as soon as they emerge, since onion seedlings are delicate and particularly susceptible to damping off. Transplant your seedlings outdoors into well-drained, highly fertile soil in a location with full sun when they reach pencil thickness in mid to late spring.

Around the expected harvest date for your particular variety, check bulbs for maturity regularly and harvest once the bulbs have sized up and a skin has formed. Some varieties are also great harvested before the fully mature stage for "baby" onions, but use these quickly, since onions without a mature skin will not keep long. 

Onions (Allium cepa) are biennial, meaning they flower in their second year after overwintering. If you live in an area where the ground freezes, you will need to dig up the plants you want to save seed from and bring them inside somewhere with temperatures between 40 and 50 degrees F, then plant them back out once the ground thaws. If the ground doesn’t freeze where you live, just cover your onions with row cover for the winter. They will send up flower stalks as the weather warms up in spring. Onions are insect-pollinated, so they need to be separated from other Allium cepa varieties by at least 800 feet in order to save pure seed. If you can’t be sure they are isolated by distance, you can place bags over the blossoms to prevent insects from reaching them, and hand pollinate by moving pollen from one flower to another with a paintbrush. Once the flower heads have turned brown, and black seeds are visible within, clip the heads and shake the seeds out into a container. Make sure the seeds are completely dry before storing in an airtight container in a dark, dry location. Onion seeds typically don’t remain viable more than 1-2 years, so use your seeds soon!