Ailsa Craig Yellow Summer Onion

Hybrid Status

open pollinated

Days to Maturity

110 days

Compare with other Yellow Summer Onions

From early May through October 31, items shipping from our garden seeds warehouse ship twice a week, usually Tuesday and Thursday. For quickest turnaround time order online by noon Monday or Wednesday.

Onions

All the varieties we list are suitable for northern growers. If you live farther south, note our latitude specifications at the end of each description.

• Long-day: Must be north of 36° latitude, though some long-day types perform best north of 40°. These onions need 14-16 hours of sun a day to trigger bulb formation. May not perform well in continually hot soil temps.
• Intermediate-day: Also called day-neutral onions, generally need 12-15 hours of daylight to bulb. Some can do well in parts of the upper southern U.S. all the way up through Maine. Others are best for mid-latitudes only (35-40°). All intermediate-day onions in our catalog have performed well repeatedly in our Maine trials.
• Short-day: Suited for the South, below latitude 36°, bulbing when the day length measures between 10–12 hours. We don’t offer seed for short-day varieties.)

About 200-250 seeds/g, 5,700-7,000 seeds/oz.

Growing Onions

Shallow rooted, onion require rich weed-free soil and consistent water. All other factors being equal, onions grown from seedlings will grow bigger and resist disease better than set-grown onions.

• Planting: Plant seedlings and sets in spring as soon as soil is workable (onion plants come with planting directions). Onions survive light frosts.
  • Seedlings: Set seedlings out in shallow trenches 1–2" deep. Plant 6–8" apart, with 1–2' between rows.
  • Sets: Plant onion sets 3" apart in rows 1' apart. Thin to 6" apart as they grow (or plant them 4–6" apart if you don’t want to thin).
• Growing: Mulch when they are 1' tall. During the season, pull any plants that begin to bolt and use them as scallions. It’s a good idea to sidedress once or twice a season, especially close to summer solstice.
• Harvest: After half the onion tops fall, push over the remainder and harvest within a week.
• Curing: Field-cure in the sun about 10 days until dry, covering with a tarp in wet weather. In the event of extreme heat or prolonged damp conditions, we recommend sheltered curing in a well-ventilated barn or greenhouse. Curing is essential for long storage.
• Storage: Store cured onions in mesh sacks in a cool dry well-ventilated place, periodically removing sprouting or rotting bulbs. Ideal storage conditions are temperatures at 32° with humidity of 60–70%. If you can’t do that, work to get a total number of 100. For example, at temperatures from 50–55°, humidity should be 45–50%. In spring, put your remaining onions in the fridge to extend storage until your new crop is ready.

Note: Onion seed is short-lived. Retest 1-year-old seed before using. Discard anything older.

Alliums

Alliums are heavy feeders and want generous amounts of organic matter, fertilizer and water. Late transplanting and poor fertility can result in small onions or failure to form bulbs. Alliums are notoriously intolerant of weeds. Slugs love to munch them, and in areas above 40° latitude, root maggots may be a problem.

Diseases:

• DM Downy Mildew
• PR Pink Root
• ALERT: Leek Moth is emerging as a serious pest potentially affecting all Alliums in the Northeast. Consult your local Cooperative Extension for more info.

Growing Alliums From Seed

• Timing: Start allium seeds indoors in February or March.
• Minimum germination soil temperature 45°; optimal range 60-70 °. We discourage using bottom heat because alliums germinate poorly in soil temps above 70°.
• Transplant: in spring soon after the ground can be worked

Note: Allium seed is short-lived. We do not hold over hybrid onion seed because of precipitous decreases in germination. Test 1-year-old seed before using. Discard anything older.

Germination Testing

For the latest results of our germination tests, please see the germination page.

Our Seeds are Non-GMO

All of our seeds are non-GMO, and free of neonicotinoids and fungicides. Fedco is one of the original companies to sign the Safe Seed Pledge.