I used to place onions in the same category as potatoes when it comes to growing them in our garden. It's so easy to buy fresh onions in markets and grocery stores, why bother growing them?
But then I started to try different varieties and I was hooked. I've tried round, torpedo-shaped, flat-shaped, and softball-sized onions over the years. They all have unique characteristics.
When growing onions in Connecticut, always look for long day or day neutral varieties. These form onions in response our longer days in summer. Short day varieties, such as Vidalia, are better grown in the South.
Then, decide if you want storage or sweet onions. Pungent or storage onions, such as Copra, can last six months in a cool basement. Sweet onions, such as Walla Walla are best eaten after harvest. Don't forget to try some cool heirlooms like the Cipollini and Red Torpedo, too.
You can start onion seeds indoors or buy plants or sets in spring. Sets and plants are easier to plant, but there are fewer varieties. Growing onions from seed is easier than you'd think. Start seeds 8 to 10 weeks before your last frost date. That would be in February for most of the state. Plant six seeds in 2-inch diameter pots placed under grow lights.
Keep the seedlings well watered and lightly fertilized. If the onion seedlings start getting tall, give them a haircut and use the cuttings in a salad.
Two weeks before your last frost date, prepare a raised bed amended with compost and plant the individual seedlings six inches apart. Keep them well watered and weeded.