Choosing the Right Onion for Your Garden Posted on 19 Nov 09:01 , 1 comment
If you are interested in growing bulbing onions, it is important to understand the different factors such as temperature and daylight hours. Soil moisture can affect onion bulbing, so even a properly selected variety needs good conditions for success.
From seed, onions usually germinate in 4 to 10 days under optimal conditions. Soil temperature should be a minimum of 55°F and up to 75°F.
Onions are adapted to a wide range of temperatures and they are frost tolerant. Leaf, root, and bulb development occurs in cool temperatures between 55° to 75°F. Optimal onion leaf growth occurs at 68° to 77°F. Once bulbing has begun onions easily tolerate temperatures higher than 75°F.
Daylight hours stimulate the onion plant to start making a bulb. Different onions require a certain amount of daylight hours.
Bulbing Onions are classified as
Intermediate day or Neutral
Long-day onions need about 14 to 15 hours of daylight to bulb. Excellent for Northern Growers (Zone 6 and colder).
In cold regions (zone 5 and colder), plant in early spring as soon as the ground is workable, and harvest in mid- to late summer.
Intermediate Day onions start bulb formation at 12–14 hours of daylight. Great for most zones. Plant in early spring in colder regions, in fall in warm regions.
Short-day onions need 10 hours of daylight. Require mild winter climates (Zone 7 and warmer).
Short-day onions: In zone 7 and warmer, plant in fall, grow through winter, harvest in late spring.
Traditional companions for onions are lettuce, tomatoes, and herbs such dill, parsley, or mint. Chamomile and summer savory as companion plants purportedly improve the flavor of onions.
Now that you have the info on different factors when growing onions, let's talk about specific varieties
Bunching Onions are not classified by daylight hours and usually mature much earlier. These varieties can be grown in all regions/zones. These include
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