How to Grow Onions in Pots/Containers


Onions: a staple ingredient in our kitchen, packed with a punch of flavor and a world of benefits. Not only do they enhance our dishes, but they also provide an array of health benefits.


They can be grown easily at home, and in this case, we’re going to focus on growing them in pots.

Why grow onions in pots, you might ask? There are several reasons. Maybe your garden space is limited, or you live in an apartment with no garden at all.

Perhaps you want to control the growing environment more precisely. Or maybe, you just love the convenience and the joy of plucking fresh onions from your own balcony or windowsill.

Whatever your reasons, growing onions in pots is a fantastic, rewarding hobby that anyone can take up. And here, we’ll guide you through every step of the process.

So, let’s dive into the world of onion cultivation and uncover the secrets of growing luscious, flavorsome onions right in your home.

How to Grow Onions in Pots/Container

Growing onions in pots is a simple, rewarding task that requires a few essential elements.

In this step-by-step guide, we’ll unveil how you can cultivate, care for, and harvest your own potted onions, transforming a humble pot into a tiny onion farm.

Choosing the Right Types of Onion

To set the stage for a successful onion harvest, selecting the right variety of onion is crucial. Not all onions are created equal.

Some types thrive in pots, while others prefer the open ground. For container gardening, smaller, faster-maturing onion varieties are usually a better choice.


Spring onions, also known as scallions, are a great pick. They’re versatile, grow quickly, and don’t need as much space as other types.

Shallots, which produce a cluster of bulbs from a single planted bulb, also do well in pots. Other good options include pickling onions or smaller varieties of bulb onions.

Getting Started: What You Will Need

To kickstart your potted onion garden, gathering the right materials is the first step. Here’s what you’ll need:

Choosing the Right Pots: Size and material matter when choosing pots for your onions. Opt for pots that are at least 10 inches deep and 12 to 18 inches wide. This provides ample space for the onions to grow.

Pots can be of plastic, terracotta, or ceramic, but ensure they have good drainage holes to avoid waterlogging.

Type of Soil Required for Onion Cultivation: Onions thrive in well-draining, nutrient-rich soil. A mix of good quality potting soil and compost works well. Avoid using garden soil as it tends to compact, reducing aeration and drainage.

Onion Seedlings or Sets: Pros and Cons: Onions can be grown from seeds, seedlings, or sets. Seedlings are young plants, while sets are small onion bulbs. Sets are easier and quicker to grow but may not offer as much variety.

Seeds take longer but allow for a wider choice of onion types. Weigh the pros and cons based on your needs and time constraints.

Essential Tools and Supplies: Prepare gardening gloves, a trowel for planting, a watering can with a gentle rose, and organic onion fertilizer.

These tools will make the planting process easier and keep your onions happy and healthy. A pair of shears would also come in handy for harvesting.

Preparing Your Pots for Planting

Getting your pots ready for planting is a critical step. Here’s how to do it right:

Positioning Your Pots for Optimal Sunlight: Onions need plenty of sunlight, at least 6 hours per day. Place your pots in a location that receives ample sunlight. Balconies, patios, windowsills, or sunny spots in your garden are ideal.

Remember, adequate sunlight ensures healthy growth and a bountiful harvest.

Preparing and Filling Your Pots with Soil: Begin by filling your pot up to one-third with a well-draining potting mix. Add some compost for a nutrient boost.

Mix it well. The pot should be filled to about an inch below the rim, leaving space for watering.

Arranging Proper Drainage System: Good drainage is key for healthy onion growth. Ensure your pots have adequate drainage holes. If not, drill some in.

To prevent soil from washing out, cover the holes with a piece of mesh or broken pottery. You may also add a layer of small pebbles at the bottom to improve drainage.

Planting the Onions

Now that your pots are ready, it’s time to get your onions in the soil. Let’s explore how to do this:

When to Plant Onions: Onions are cool-season plants that can endure short bouts of frost. The ideal time to plant onions is in early spring or late summer/early fall, depending on the type of onions you’re growing and your region’s climate.

How to Plant Onion Seedlings/Sets: If you’re using sets, press them gently into the soil, pointy end up, until they’re just covered. For seedlings, dig a small hole and place the seedling in it, covering the roots but leaving the green shoots exposed. Planting depth is usually about an inch into the soil.

Spacing Considerations: Space is crucial for onions to grow well. If you’re growing bulb onions, leave around 3 to 4 inches of space between each plant. For spring onions, a spacing of 1 to 2 inches should suffice.

Proper spacing allows for good air circulation, reduces disease risk, and ensures each onion has enough nutrients and room to grow.

Care and Maintenance of Onion Plants

Nurturing your onions post-planting is key to a successful harvest. Let’s discuss the essential care and maintenance tips:

Watering: Frequency and Amount

Onions need consistent moisture but dislike waterlogging. Water them when the top inch of soil feels dry to the touch.

Ensure the water penetrates the soil deeply rather than just wetting the surface. Avoid overwatering, as it can lead to rot and other diseases.

Nutrient Requirements and Fertilization Schedule

Onions need a rich, well-fertilized soil to grow well. Use a slow-release organic fertilizer at planting time.

For heavy feeders like onions, another round of fertilizing may be needed midway through their growth. Always follow the instructions on the fertilizer packaging.

Dealing with Pests and Diseases

Common pests for onions include onion maggots and thrips. Regularly check for pests and use organic pest control methods to manage them.

As for diseases, maintaining good plant health through proper watering and spacing can prevent most problems.

Thinning and Pruning Techniques

If you’ve sown seeds directly, you may need to thin your onions to provide enough space for growth. Remove the smaller, weaker plants and leave the strongest to grow on.

As for pruning, it’s usually not required for onions, but if leaves become damaged or diseased, they can be cut off for plant health.

Harvesting Onions from Pots

When your onions have grown and matured, it’s time for the most rewarding part – the harvest. Here’s how to proceed:

Signs Your Onions Are Ready for Harvest

Onions signal when they’re ready to be harvested. The tops will start to yellow and fall over, indicating they’ve stopped growing. This is usually about 5 months after planting.

Spring onions can be harvested earlier when they’ve reached the desired size.

How to Harvest Onions Without Damaging Them

To harvest, gently loosen the soil around the bulb with your fingers or a hand trowel. Pull the onion gently but firmly. Do not yank, as this can damage the bulb and roots.

Post-Harvest Care

After harvesting, clean off any soil and let your onions dry in a sunny, airy spot for a few days. This process, known as curing, helps extend the storage life of onions.

Once the outer skin is papery, trim the roots and store your onions in a cool, dry place. Now, they’re ready to spice up your dishes with homegrown goodness!

Storing and Using Homegrown Onions

Congratulations on your harvest! Now, let’s explore how to store and use your homegrown onions:

Proper Techniques for Storing Onions

Onions should be stored in a cool, dry, and well-ventilated area, away from direct sunlight. You can store them in mesh bags or baskets for good airflow.

Avoid storing onions near potatoes, as they can accelerate each other’s spoilage. Properly cured and stored onions can last several months.

Suggested Uses for Freshly Harvested Onions

Freshly harvested onions can be used in a myriad of ways in your kitchen. Dice them up for salsas, slice them for sandwiches, sauté them for stir-fries, or caramelize them to bring out their sweetness.

If you’ve grown green onions or scallions, they’re fantastic in salads, as garnishes, or in Asian dishes. The options are endless with your delicious, homegrown onions. Enjoy the fruits of your labor!

Common Problems and Solutions in Growing Onions in Container

Even with the best care, you might encounter some issues while growing onions in pots. Let’s address common problems and their solutions:

Identifying and Addressing Common Diseases

Onions can suffer from fungal diseases like onion blight or bacterial soft rot. To prevent these, ensure good air circulation, avoid overcrowding, and do not overwater.

If disease strikes, remove and discard affected plants immediately to prevent spread.

Pest Management and Control

Common pests include onion thrips and onion maggots. Regularly inspect your onions for signs of damage.

For thrips, use insecticidal soap or neem oil. Onion maggots can be prevented with beneficial nematodes or diatomaceous earth.

Troubleshooting Growth and Harvest Issues

If your onions aren’t growing as expected, check your watering, sunlight, and fertilizing practices. Too much or too little of these can hinder growth.

If bulbs are small at harvest time, they might have been overcrowded or lacked nutrients. Use these lessons to adjust your care routine for the next growing cycle.

FAQs about Growing Onions in Containers/Pots

Can all onion varieties be grown in pots?
Not all onion varieties are suited for pot cultivation. Smaller, faster-maturing types like spring onions or shallots do well in pots. Larger bulb onions can be grown too, but they need larger pots and more care.

How big should the pot be for growing onions?
For most onions, a pot that is at least 10 inches deep and 12 to 18 inches wide will work well. This allows enough space for the onions to grow and mature properly.

Can I use garden soil for growing onions in pots?
It’s better to use a potting mix rather than garden soil when growing onions in pots. Garden soil can compact in containers, restricting aeration and drainage. A well-draining potting mix combined with compost is ideal.

Why are my potted onions not forming bulbs?
Several factors could cause this issue: not enough sunlight, overcrowding, improper watering, or inadequate nutrients. Ensure your onions get at least 6 hours of sunlight, are spaced properly, and receive consistent watering and sufficient nutrients.

How often should I water my potted onions?
Onions need consistent moisture. Water them when the top inch of the soil feels dry. Overwatering can lead to diseases and rot, so it’s important that your pot has good drainage.

Do I need to fertilize my potted onions?
Yes, onions are heavy feeders and benefit from regular fertilization. Use a slow-release organic fertilizer at planting time, and consider a second application midway through the growing season.

What pests and diseases commonly affect potted onions?
Onion thrips and onion maggots are common pests. Diseases include onion blight and bacterial soft rot. Regular inspection, good pot hygiene, and organic pest control can help manage these issues.

When should I harvest my potted onions?
Onions are usually ready to harvest when their tops begin to yellow and fall over. This indicates they’ve stopped growing. The exact timing will depend on the onion variety and growing conditions.


How can I store my harvested onions?
After harvesting, cure your onions in a sunny, well-ventilated spot for a few days, then store them in a cool, dry place. They can be stored in mesh bags or baskets to ensure good airflow.

Can I grow onions indoors in pots?
Yes, onions can be grown indoors in pots, as long as they receive enough sunlight, preferably from a south-facing window. They need at least 6 hours of sunlight daily. If you don’t have enough natural light, you could use grow lights to supplement it.

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