Imagine going out to your patio or porch and digging up a fresh onion bulb or clipping the green tops for garnish. Veggies from a garden are so much better than those from the grocery store, and you don’t need a lot of space to grow them. Growing onions in containers is easier than you realize, as long as you give them the right amount of care.
Onions (Allium cepa) take up very little space. In fact, it’s possible to grow several onions in one pot if it’s wide enough.
Not only that, but there are many onion varieties to grow, from sweet, yellow, white, and red onions to leeks, shallots, scallions, and spring onions. With so many choices, you’ll have plenty of onion bulbs and green onions for your kitchen.
Onions grow well in everything from a decorative garden pot to a gallon bucket or plastic tub. The key is to give them a good amount of sunshine and some tender loving care.
- Container Gardening with Onions
Container Gardening with Onions
Thinking you cannot grow your own veggies simply because you don’t have a backyard is a common mistake. The process is the same whether you plant red onions vs shallots or Vidalias. We explain how to grow onions in a container using different methods, how to care for them as they grow, and when to harvest your onions.
Different Ways of Planting Onions in Containers
One of the coolest things about planting onions in containers is that there is more way than one to go about it. While many other veggies grow from seed alone, onions grow from seeds, sets, and scraps, making them one of the best vegetables for container gardens.
There are three ways of growing green onions in containers. The most common way to grow veggies is from seeds, and onions are no exception. Seeds are cheap to grow, but it’s one food you can grow indoors several weeks before the last frost.
Another way to grow onions is to purchase onion sets. These are available in garden centers, and there are usually different varieties to choose from.
They are small onion bulbs grown from seed the year before and about the size of a nickel. These are the easiest to grow, and you don’t have to start them indoors.
Another way to grow onions is to plant them from the leftover portion you usually throw into the garbage or compost pile. Growing them this way is a great way to recycle and a fun project to do with kids.
Before planting onions, it’s important to know the differences between them. Short-day onions are usually sweeter and grow in areas where the day length reaches ten to 12 hours.
Long day varieties require up to 16 hours of daylight each day and are good for storing.
How to Grow Onions in Containers from Seeds
While growing plants from seeds take a bit more time and patience, it’s the most inexpensive way to grow a container garden. Here is how to grow onions in containers by starting them from seeds.
Start by deciding whether you plan on growing long-day varieties or short day onions, and choose the seeds accordingly. When growing onions from seed, start your seeds in the early spring, approximately seven weeks before the last frost.
Whether growing shallots indoors or outside or planting a different type of onion, fill a seed tray with damp potting soil and press two seeds into each compartment, about a quarter-inch deep. Cover them with dirt and set the tray in a sunny windowsill where the temperature is warm.
After they germinate and grow three or more leaves, transplant them into a container that is ten inches deep and a foot or wider, depending on how many onions you plant.
Space the onions four to five inches apart while transplanting, pat the soil down around the plant’s base, and water them to help the onions settle.
Harden them off slowly by moving the container outdoors for a couple of hours each day for a week and then setting it in a sunny patio area.
Growing Onions in Containers from Onion Sets
If you don’t have the patience to wait for seeds to grow, consider buying onion sets from one of your local garden centers. Here is how to plant onions in a container by starting them from small bulbs.
Choose a container or pot large enough to accommodate the number and spacing of the onions you plant. Pick one that is ten inches deep and a couple of feet in diameter.
In the spring, after the last frost, fill the container with potting soil and make a one-inch deep hole in the soil. Place a bulb in the hole and cover it with dirt.
To plant more than one onion, space them four to five inches apart. Water them and set them in a full sun area of the porch or patio.
How to Grow Onions from Onions in Containers
One of the most fun ways of planting onions in containers is to grow onions from onions at home from the onion parts you normally toss in the trash. Here is how to regrow an onion in a pot from the leftovers of your favorite grocery store onion.
After slicing up an onion for a meal, planting onions from onions is simple. Save one inch of the onion bottom with the roots. Leave the section out to dry for 12 to 24 hours until it is calloused to the touch.
Fill a jar or cup with water, take four toothpicks, insert one into each side of the onion, and balance it on the jar’s rim so the onion bottom sits in the water. Set the jar in a safe area for three to four days or until it grows small roots from the bottom.
In the early spring, prepare a pot with drainage holes by filling it halfway with dirt. Remove the toothpicks from the onion and set it, root side down, in the soil.
Pour dirt over the top of the onion until it is about two inches from the top of the container and water it to help the root system settle. Set it outside in a full sun area and water it as needed.
Giving Your Onion Plants Care
Plant maintenance is essential when learning how to grow onions in containers. Without proper care, onion plants suffer and die. Here is everything your onions require to grow and thrive.
Fertilizing is necessary for onion growth, so feed your onion with a nitrogen fertilizer right after planting. Then, fertilize it once every two weeks until the bulb starts poking out of the dirt.
After the onion sprouts, cover the soil with mulch to retain moisture and halt weed growth. Since they have a shallow root system and dry out easily, give your onion plants one inch of water each week and pull out weeds as soon as you spot them.
Common Problems When Growing Onions
Unfortunately, you still have more work to do after you plant your onions and give them water and nutrients, whether you are growing yellow onions or one of the many other varieties.
Just like any other plant, onions occasionally suffer from problems like disease and pests. Here are some signs to look for and ways to remedy the issue.
Various problems affect a garden after you plant onion bulbs, and container onions are no exception. Plants that produce many leaves without bulbs signify that you planted them when the weather is too warm.
If your plant has small onions that look normal at the end of the growing season, there is a good chance you planted the wrong variety of short-day or long-day onions for your region.
Leaves that are silvery and white are a sign of thrips. These insects are common during hot weather, and an insecticidal soap works well to kill them.
Onion maggots are another common problem. The way to know if an onion is bad after an experience with onion maggots is limp, yellow leaves, and soft rot on mature onions. The best way to prevent this from recurring is to discard the dirt from the container and use fresh soil for your next planting.
When are Onions Ready for Picking?
Unlike other vegetable plants, onion bulbs grow underground, and it isn’t easy to know exactly when they are ready for picking. Learn how long it takes for onions to grow and when they are ready for harvesting.
Onion seeds and sets take about three to four months for complete bulb formation. Start checking the green tops of the onions at this time, and when you notice they turn brown and wilt, it’s time to harvest them.
Pull onions that have bolted, or grown flower stalks, right away and do not store them. Carefully pull up or dig the onions out of the dirt with the onion tops intact.
Shake off the soil and set them in a clean and dry place to cure for two to three weeks before you store onions. If a recipe calls for chives and you don’t have any, onions are a great substitute for chives.
Container gardening with onions is a great way to grow your own veggies, and you don’t need a fancy garden pot to grow them.
It’s easy to grow onions in the spring, early summer, late summer, or fall, depending on where you live, and enjoy a flavorful harvest at the end of the growing season.
Growing onions in containers is not only simple to do, but they take up less space than you think, so why not share our container onion growing guide with your friends and family on Pinterest and Facebook?