Successful Onion Growing

Sliced on salads or burgers !

Added to soups and sauces!

Home grown onion taste better and store longer.

Find out how the choose the right varieties.


What Do You Want to Know About Onions?

Choose the Right Onion Variety for Your Location

Onions come in three types –  Long, Intermediate and Short Day varieties.

Long Day require 14 or more hours of daylight to form bulbs. They are grown in Oregon, Idaho, Wyoming, Nebraska, Iowa, Illinois, Indiana, Ohio, Pennsylvania, New Jersey and state north of these.  

Intermediate require 12 to 14 hours of daylight and are best grown in zones 5 and 6. They will grow well in zones farther north or south, however.

Short Day onions produce bulbs with 10 to 12 hours of daylight. They grow well in Southern California, Arizona, New Mexico, Oklahoma, Arkansas, Tennessee, North Carolina and States south of these. 


Where should I plant my onions?

  • in a well drained area
  • in soil with some organic material
  • in heavy clay, grow in beds
  • near water source
  • have the ground prepared the fall before,
    if possible
  • full sun 

How Do I Prepare Raised Beds for Onions?

In many gardens, a raised bed for onions is a great idea because the bed is drier and warmer in the spring than the ground.

Ideally, the bed should have loose soil 12 inches deep. A minimum of 6 to 8 inches is required for onions.   

Avoid filling the bed with only ordinary garden or top soil, because the surface will crust over
and the bed will dry out faster. 

Add potting mix, garden compost and a bit of sand.
Mix 1 part organic matter (peat moss, compost, etc.) to 1 part sand or perlite to 2 parts soil.

Onions require lots of organic matter or additional fertilizer. A side dressing of fertilizer three times during the growing season helps to form bulbs. 

Can I Grow Onions in Pots?


Use a container soil mix with time release fertilizer.

Add much when the bulbs get larger to retain soil moisture. 

The potted onions may require more water and fertilizer than the in ground or bedded plants. But be careful not to water too much or add large amounts of nitrogen. 

Each onion should have three inches of space between it and other onions or the side of the pot. 

How About Growing in the Ground?

It’s best to prepare the ground in the fall, so you can plant as early as possible in the spring.

Year One – test the soil to find out what nutrients need to be added. It’s best to work with you extension agent to know how much nitrogen should be applied. 

Avoid areas of heavy weeds or where onions have been plants before if possible

Year Two – In the spring,

Keep weeded but avoid disturbing the onion roots.

Keep moist. If planting seeds, 1/10 of an inch of water several times a day may be a good choice for good seedling growth.

How Do I Plant Onions?

  • Plant as early as the ground can be worked. 
  • For seeds plant 1/4 to 1/2 deep in rows 12 to 18 inches apart. Thin to 3 to 4 inches apart.
  • For sets and bulbs plant 2 inches deep, 3 to 4 inches apart in rows at least 6 inches apart. 
  • Seeds can be started indoors 10 to 12 weeks before planting outside.
  • Water the seeds, starts and bulbs in.

Getting the most onions

Provide 1-2 inches of water per  week. 

Stop watering when the bulbs are full sized and the leaves fall over.

If you have a short growing season, plant starts or bulbs.

Weed very carefully, chopping weed of rather than pulling. or add 3 to 4 inches of mulch to prevent weeds.

Side dress with urea once or twice during the season after roots are well developed. Fertilize 6 inches away, never directly on the roots. 

When Do I Harvest Onions?

Harvest when half the tops have fallen over and are dry. 

Cure the onions on the ground if warm dry weather is forecast. 

Or bring indoors to cure. Keep warm at 75 degrees F or warmer, for 2 to 4 weeks. The outer layers will be dry and the neck tight and harder. 

Store under 40 degrees to prevent sprouting. 

If you take care of your plants, you can look forward to tons of onions.

A 100’ row of garden peas will yield around 200 to 250 pounds of onions.