Alliums – onions, shallots – are a culinary staple and great to have available for the whole season – whether at your market stand or in your garden. Not only are alliums tasty, but they are also highly nutritious, believed to have anti-inflammatory, anticholesterol, anticancer, and antioxidant properties.
Planting for a Long Harvest Window
All alliums should be seeded at the same time – in the early spring – but by planting varieties with different maturity dates, you can plan for the widest possible harvest window.
- Scallions for the Early Season: Scallions – like Evergreen Hardy, and Parade– will form thin, straight, non-bulbing roots a little over 2 months after seeding. Scallions can be eaten all the way up the stalk; both the succulent, green tops and the sweet, mild roots are tasty both cooked and raw. Red Baron is a bulbing onion that can also be grown as a scallion.
- Fresh Market Onions for Summer Grilling: Sweet onions – like Yellow Cipollini, Gladstone and Siskiyou Sweet Walla Walla – form nice sized bulbs ready for harvest 80-100 days after seeding. These sweet, mild onions won’t store well, but they are great for fresh eating, grilling or sautéing. Try transplanting a stand of Gladstone or Siskiyou Sweets in mid-April at 4” apart, then beginning in July start thinning out the rows by harvesting every other or every third onion. You’ll get nice sized fresh onions for bunching, and the ones left in the row will continue to bulb for a later harvest. Red onions – like Red Baron and Red Wing – can be planted similarly to add color to your display or your salad.
- Storage Onions for Fall and Winter Eating: Many choices are available for storage onions which are typically harvested in the late summer/early fall once the tops have died down, then cured under warm, dry conditions to set the skins and improve storability.
- We’re excited to introduce Sedona: a gorgeous hybrid Spanish storage onion. Spanish type onions are yellow-skinned, mild and sweet. Sedona’s skin has a delicious warm brown color; in our trials it has been a stand-out for high yields and hard bulbs which indicates good storability.
- If you’re looking for a high-quality open-pollinated yellow storage onion, then you won’t find better than Dakota Tears. This variety has been selected and improved for over twenty years by organic seed farmer and breeder David Podoll on Prairie Road Organic Farm in North Dakota. The result is an open-pollinated onion that compares with the hybrids in terms of yield and disease resistance. In our 2011 trials, the tops on this variety looked great long into the season, although the size uniformity was somewhat variable. Dakota Tears was selected as one of the top 10 varieties of 2010 by Organic Gardening magazine.
- Shallots for Flavor and Storage: Smaller than onions in size, shallots certainly aren’t lacking in flavor! Store shallots in cool, dry conditions and they will last for months. Ambition is a hybrid shallot with a blocky shape and reddish brown skin. Conservor, also a hybrid, has a pinker hue and more tear-drop shape. High sugars make both of these varieties great for caramelizing. Shallots can have a reputation for being difficult to work with in the kitchen – small and hard to peel – but in our trials we were very impressed by the size of both these varieties and by their easy-to-peel skin.
Allium Seed Starting Tips
In northern climates, onions are started in the spring. Because they are slow growing and have a non-existent leaf canopy, they aren’t good at out-competing weeds. Starting onions in the greenhouse and planting them as transplants is recommended.
- Start onions for transplanting 10 to 12 weeks before the last frost date in your area.
- Sow seeds thickly in flats or 1” cells.
- When plants emerge, thin to approx 1/8” apart.
- When seedlings reach 5” tall, trim tops to 1” to increase girth.
- When seedlings are pencil-thick, harden-off by exposing them to outdoor conditions while maintaining regular watering and fertility for one week before planting;
- Transplant 4-6” apart and 1-2” deep.
About Day Length Sensitivity in Alliums:
- Short Day: Best for planting in the south, where hours of sunlight per day averages 10- 12 hours. (Note: you can grow short day onions in northern latitudes but they will start to bulb as soon as day length reaches 12 hours and you’ll get smaller onions.)
- Intermediate Day: These onions start to bulb when day length reaches 12 to 14 hours. These varieties will not do well in the far south, but will do well in the rest of the country.
- Long Day: In northern latitudes (north of 35º), with long summer days, plant long day onions, which begin to bulb when the days reach 14 to 16 hours in length.