Onions, shallots and leeks are all part of the Alliums family—and treasured for the flavor they add to recipes. They’re all easy to grow in the garden and perform best when planted in full sun. They have differences, though.
Onions are a garden favorite—and can be eaten raw, in salsas and salads, and cooked into your favorite recipes. Home gardeners can choose from onion varieties that are mildly sweet to pungent. Because onions are affected by the amount of light they receive, some grow better in the North, while others perform better in the South. Short-day onions begin forming bulbs when daylight lasts 10-12 hours and are often the sweetest and best for eating raw. They’re most often grown in the South. Long-day onions begin forming bulbs when daylight lasts 14-16 hours. They are usually pungent, often store well for many months, and are usually grown in the North. Day-neutral onions are a cross of the two types. Onions can be started from seeds, sets and plants.
Shallots have a subtle flavor that is much milder than onions or garlic—and are a favorite of gourmet cooks. Their flavor really shines when sautéed in butter or olive oil. Like green onions, their green shoots and bulbs are edible—and the green shoots can be used as a green onion or scallion substitute. While shallots can be grown from seed, growing them from sets is often easiest. After harvest, cured bulbs can be stored for up to six months.
Leeks look like overgrown green onions, but have a milder, more delicate flavor than onions. The white base and green stalk are used for cooking in creamy soups, fresh, stocks and more. Leeks can be direct seeded outdoors or started indoors and transplanted into the garden. Thinning during the growing allows the plant to grow much larger. After harvest, leeks can keep in the refrigerator for up to 2 weeks—or they can be dried for storage.
Onions, shallots and leeks are not considered interchangeable when it comes to cooking. Make sure you use whichever your recipe calls for, as the distinct flavor of each may alter the taste of your dish.