How to Grow Onions in Containers

Onions (Allium cepa) are not only versatile vegetables that add zest to your recipes; they’re also excellent container plants. Whether you plant onion bulbs in containers or a vegetable garden, they need the same types of soil and climate conditions. Follow these tips for growing onions in containers either in your house or on your patio.


Choosing Onion Varieties

Two of the best onion varieties for container planting are green onions and boiler onions, also known as pearl onions. These varieties are small, so you don’t need large pots to grow them.

  • Green onions – Whether you call them scallions or salad onions, green onions are young onion plants grown from seed. You can buy them in the supermarket in the produce section. You’ll notice that the green onions have small white bulbs with roots still attached.
  • Pearl onions – These onions are only 1 to 2 inches in diameter and look like miniature onions. Many people use them in soups and stews or just boil them as a side dish. Pearl onions don’t have roots like green onions do, so they take a little longer to grow.

Planting Green Onions in Pots

To get your onions started indoors, you need a few supplies. Gather the following items, and you’ll be on your way to growing onions for using all year long:

  • Six-inch pot with a wide mouth
  • Nutrient rich potting soil
  • Green or pearl onions

Once you have your supplies, choose a sunny location in a window or outside on your patio or porch. Follow these steps for planting your onions:

  • Fill your pot about half way with potting soil.
  • Moisten the soil, but make sure it’s not saturated.
  • If you’re planting scallions, trim off the onion tops about 1 inch above the bulb.
  • Place your onions or onion plants about 2-inches apart in your pot. Make sure the roots face down into the soil.
  • Spoon more soil around the onions, just covering the bulbs
  • Gently press the soil down.

Once you’ve planted your onions, place the pots in the sunny location you chose. They need up to seven hours of sun per day.

Growing Onions in Containers with Water

Growing onions in water is another option, rather than using potting soil. It’s amazing to watch onions grow in water. If you want to see the onions roots forming as they grow, use a glass container, such as a mason jar to grow your onions. Choose a jar that has a wide enough mouth for the onion to sit on the rim. The bottom of the onion should be able to rest on the rim with its bottom in the water. Just add water to the jar and place it in a sunny spot.