The two most important factors to consider when choosing onion (Allium cepa) varieties are the onion’s flavor and your garden’s location. Onions are particular about how much sunlight they get, forming bulbs in response to the number of daylight hours. As a result, onion varieties are classified by day length - long day, short day, or intermediate day - as well as by taste - sweet (which are good for fresh eating only) or pungent (which are good for storing). In general, short-day onions grow well in the southern United States, long-day onions grow well in the northern United States, and intermediate-day onions grow well in the in-between regions.

Following is a list of our favorite onion varieties. The days to maturity are from either directly seeding in the garden or setting out (placing outdoors) sets or plants. You usually plant short-day onions in fall to grow through the winter, so they take longer to mature than other types. You plant long- and intermediate-day onions in spring. All the onions in the following list have yellow skin and white flesh unless otherwise noted.

• ‘Candy’: Sweet, intermediate-day, widely adapted hybrid also available as a plant. Matures 85 days after seeding.
• ‘Granex 33’ (Vidalia): Classic hybrid, sweet, short-day onion also available as a plant. Matures in spring 180 days after fall seeding.
• ‘Red Burgermaster’: Hybrid, red-skinned, pink-fleshed, pungent, long-day onion stores well. Matures 110 days after seeding. (The classic onion that tastes so great in sandwiches.)
• ‘White Bermuda’ (Crystal Wax): White skin and flesh matures 170 days after seeding this short-day onion. Available in a red version and as a plant.

Sulfur, not sugar, makes onions pungent or sweet. Sweet onions have less sulfur than pungent varieties, so they taste sweeter. Although the sulfur can make the onion more pungent, it also makes those varieties great storage onions. To keep your sweet onions as sweet as they can be, don’t apply any sulfur fertilizers and keep the onion plants stress free by controlling weeds and making sure that the plants receive enough water and fertilizer.