How to Grow Onions from an Onion

Onions (Allium cepa) are versatile, flavorful vegetables, and they are simple to regrow from other onions. If you want to grow them in your garden, use onion sets for a jump on harvesting. You can also use containers to regrow onions in the house with onions you have on hand.


Growing Onion Sets

Onion sets are small onion bulbs cultivated for re-growing onions. When you plant sets, you don’t have to plant seeds or seedlings, which saves you a lot of time and gives you a quicker harvest. Any garden center sells onion sets for you to start in your garden. Follow these steps for planting onion sets:

  • Turn over your garden soil and rake out any stones and weeds.
  • Use a hoe to dig 1 to 1.5 inch deep furrows in the soil. If you’re planting more than one row, make them about 14 inches apart.
  • Place your onion bulbs 3 to 4 inches apart in the furrows.
  • Cover them with soil or hay, letting the onion tops poke through.
  • Water the onions weekly, just enough to moisten the soil.
  • Weed around the onions as necessary.
  • Harvest your mature onions in three to four weeks.

Growing Onions from Onions

If you’re re-growing your onions in containers, you can use two different methods. One method is to grow the onion in water and the other is to grow it in soil. If you decide on using water, you’ll grow green onions from the onion bulb. If using soil, you can grow either green onions or onion bulbs.

Water Method

All you need to grow onions in water is a jar or glass that has a rim the onion bulb can rest on. Follow these tips for re-growing onions in water:

  • Fill the jar with water just enough so the onion bottom stays wet.
  • Peel off the papery skin on the onion.
  • Place it on the rim of the jar so the bottom of the onion is in the water.
  • Put your jar in a sunny spot, keeping the onion roots in the water.

You’ll soon have green onions, also known as scallions.

Soil Method

If you opt for growing your onion in a container using soil, select a container or pot that’s 6-inches deep. Follow these steps for planting your onion bulb:

  • Fill the container to about the half-way mark with a high-quality potting soil.
  • Press the onion into the potting soil about 1 to 1.5 inches deep, depending on the size of the onion. Let the onion top show through the soil.
  • Place your container in a sunny location.
  • Keep the soil moist but not saturated.
  • Your green onions will sprout within three weeks.

Whether you decide to regrow yellow onions, red onions or green onions, any of these methods will work for you.