When to Plant Onions

Onions are a healthy addition to the diet and garden, and many recipes are not the same without the flavor of these alliums. The best thing about onions is you don’t need a lot of space to grow them. Learn how and when to plant onions and harvest them at the end of the growing season.

There are many species of genus allium, including green onions, bunching onions, shallots, leeks, chives, and scallions. However, the common onion is the most widely cultivated.

There are many types of onions, from white and yellow onions to red onions, as well as long-day varieties and short day varieties, and the different types vary in sweetness.

Planting, Growing, and Harvesting Onions

With so many onion varieties, it’s no wonder they are a favorite of the home gardener. They are easy to grow from onion seeds or sets from garden centers or regrow from leftover scraps you usually throw away in the trash, and they thrive in both a garden setting and raised beds.

Home gardening is a rewarding experience, and planting onions is a great way to produce healthy, organic food. They are simple to grow in a container, raised bed, or garden and almost take care of themselves. But, what month do you plant onions? It all depends on where you live.

Like many other vegetables, onions require the right amount of sunshine and certain temperatures to thrive. They also grow better at different times of the year, depending on the hardiness zone. Find the best time to plant onions according to your location and the onion type.

How Long Do Onions Take to Grow?

One of the first steps in planting onions is understanding how long these alliums take to grow. Like other plants, there are several stages in an onion’s growth. Explore how long they take to germinate and produce onion bulbs for harvesting.

Onion seeds take seven to ten days to germinate. However, the cooler the temperature, the longer the germination process takes. After that, an onion’s rate of growth depends on how you start the plant.

If you start your onions from onion sets, they take about three and a half months to form bulbs, while onion seeds take longer to reach full size.

What Month Do You Plant Onions?

What month do you plant onions is a common question and the answer depends on the region you live in. Learn what a hardiness zone is and when to plant onions in zone 5 and other hardiness zones. When to plant shallots is the same.

The United States is separated into eleven hardiness zones, which are regions with varying types of climates. The lower the zone, the colder the climate, and the higher the number, the warmer the weather. Each area is either 10°F warmer or colder in the winter than the adjacent zone.

Gardeners use the hardiness zone map to determine when to plant onions in zone 7 compared to zone 4 or 5. If you live in zone 5 or colder, it’s a good idea to plant onions in early spring once the ground is workable. If you reside in zone 7 and up, consider fall planting for an early spring crop.

Best Time to Plant Onions

There are many types of onions, and some of them want more hours of daylight than others. Discover the best time to plant onions based on your hardiness zone, depending on whether they are long-day or short-day varieties.

Onions are cool weather crops, so the main thing to consider when deciding when to plant them is the temperature throughout the year where you live. Onions produce when grown in regions where the temperature is between 55 to 75°F.

If you live in a northern area, consider planting them in early spring. If you reside in the south, plant them in the fall.

Different types of onions also require varying degrees of sunlight. For example, long-day onions need at least fourteen hours of full sun each day and are suitable for planting in the spring, while short-day onions require ten to twelve hours of sun daily and are a good choice for southern planting in the fall.

Intermediate day onions and day-neutral onions flourish throughout the United States. However, intermediate types need ten to twelve hours of sun, while day-neutral varieties form bulbs regardless of the day length.

How to Grow and When to Plant Onions

Onions are cool weather plants that flourish if you plant them in the early spring or fall, depending on your climate. While growing onions from seeds or sets is simple, onion sets establish faster than transplanting onion seedlings. Here is how to start your onions from sets by planting them with the proper depth and spacing.

The first step is to pick which variety of onion sets to plant. Onion sets are small bulbs you can find at your local nursery. There is a wide range of onion types to choose from, including Walla Walla, Texas Early Grano, and yellow, red, and white mixed onion sets.

The best time to plant onion sets for spring planting is to prepare the garden in late March or early April before the last frost. If you prefer fall planting, start the garden and follow the way to plant onion bulbs four to six weeks before the first hard frost.

Dig a trench two inches deep and three inches wide and work an inch of compost or organic matter into the bottom of the row. Set the bulbs with the pointy side up two to six inches apart and bury them no more than an inch beneath the ground. Water them right after planting.

Caring for Onions as They Grow

Now that you understand when to plant onions in zone 6 or another region of the United States, and you start your plants at the recommended time, it’s time to give them some TLC. Find out how to care for your onions with the right amount of sunshine, water and fertilizer, and things to watch for as they mature.

Feed your spring onions vs green onions and other onion types a nitrogen-rich fertilizer once every two weeks to encourage significant bulb growth, and stop feeding the plants once the onions push away the dirt and bulbing starts.

Spread a half layer of straw to mulch the garden after the bulbs develop to stop weed growth, retain moisture, and allow air circulation. Give your plants an inch of water weekly, especially during dry conditions to prevent them from bolting.

Thrips and onion maggots are two common pests for onions. Thrips are tan-colored, tiny insects about as fat as a sewing needle – insecticidal soap effectively eliminates them. Onion maggots lay their eggs at the base of onion plants, and covering your onions with a fine mesh netting keeps them off the plants.

The best part of growing onions is onion harvest season. Spring planted onions are ready to harvest in mid-summer, and yellowing and wilting foliage are signs that they are near maturity. When the tops turn brown, it’s time to pick yellow onions. Harvest the onions by pulling them gently from the ground to prevent bruising and rotting.

Onions with flower stalks are no longer growing and are not suitable for storage. Instead, remove them from the ground and use them in recipes within a couple of days as a shallot substitute or for any dish requiring onions.

How to Make Slow Roasted Baked Onions

Onions are great for adding to dishes to add flavor and texture. However, they are even better when they are the main ingredient. Slow roasted, baked onions are simple to prepare and easy to personalize with your favorite spices and toppings.

Prepare four large red, white, or yellow onions for baking by trimming off the ends and slicing them in half horizontally. Keep the skin intact to hold the onion’s shape and protect the outside as it roasts.

Combine the water, red wine vinegar, brown sugar, salt, pepper, and one teaspoon of the rosemary in a bowl. Place the onions cut side down in the bowl to marinate overnight in the refrigerator. Consider adding minced garlic, hot sauce, or Cajun seasoning to the marinade for variety.

Remove the onions from the sauce and arrange them in a baking pan with the flat sides up. Top them with the butter and one teaspoon of rosemary and roast them for one hour in an oven heated to 400°F. Take them out of the oven, peel off the outer skins and serve hot.

Onions are easy-growing vegetables that take up little space in the garden. However, it’s essential to understand when to plant them according to your region to ensure you get the most out of your onion crop at the end of the season.

Now that you know when to plant onions so that you get to enjoy a happy gardening experience, we’d love it if you’d share our onion planting tips and gardening guide with your circle of friends and family on Pinterest and Facebook.