Although yellow onions are more popular, red onions are quickly becoming more and more popular in kitchens across the world. Red onions, as opposed to yellow onions, are sweeter and milder, and therefore are perfect in salads and salsas! If you're interested in learning how to grow red onions, keep reading this easy to follow gardening guide!

How to Grow Red Onions in The Garden

red onion harvest

Growing red onions is actually quite easy and follows the same pattern as any other type of onions. Onions are all biennials, meaning they take 2 years to complete a full life cycle. During the first year, seeds grow and form modified leaves and small underground bulbs.

In the second year, the onion bulbs mature until they're ready for harvest. Most gardeners will actually plant onion sets, which are the second year bulbs for a quicker harvest, but, if you're in no rush you can plant them directly from seed and wait the life cycle. Keep reading to find out how to grow red onions!

Planting Red Onions

  • Choose an area with full or partial sun.
  • The soil will need to be well-drained, loose, and rich in nitrogen.
  • Before planting your onions, work in aged manure or fertilizer. Onions are heavy feeders, and if well fed, will grow big bulbs.
  • When it’s time to plant, mix in some nitrogen fertilizer, and side dress every few weeks until bulbing begins.
  • Plant your onions in early spring, as soon as the last frost is over, usually in late March or April.
  • Plant the smaller sets 1 inch deep into the soil, and 4-5 inches between each plant. Each row should be 12-18 inches apart.
  • Every few weeks, fertilize with nitrogen in order to get big bulbs.
  • Stop fertilizing once the onions push the soil away and the bulbing process has begun.
  • Do not put soil back around the bulb once it has grown – the bulb needs to emerge above the soil.
  • Cover the area which mulch to retain moisture.
  • Remove any onions that have sprung flower stalks. This means that the onion has bolted and is done.
  • Water regularly to ensure sweeter, better tasting onions.

Harvesting Red Onions:

planting red onions
  • Onions will become mature once the tops become yellow and begin to fall over. At this point, you can bend the tops down to speed the ripening time.
  • Loosen the soil around the bulb to encourage drying. After a few days, turn them up and let them cure on dry ground.
  • Make sure to handle the onions carefully as the smallest bruise can encourage rot.
  • Once the tops are brown, pull the onions.
  • Harvest in late summer.
  • Allow the bulbs to dry for a few weeks before storing them in a cool, dry place.
  • Do not store with apples or potatoes.

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How to Grow Red Onions
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