Onions, a member of the allium family, is a cousin of garlic, chives, leeks and shallots. They are mostly biennials, growing vegetative the first year then blooming the second. Onions are rugged plant that can withstand some weather at below- freezing temperatures. You can plant Onions in small areas receiving full sun. Onions can be available for nearly all year round eating with a little planning. They can be grown from bulbs, also known as small dormant onion called sets. You can buy onion sets (bulbs) for $1-$2 per 100 bulbs at your local nursery. Buy onion sets that are firm and marble size that have not sprouted.

Plant Constant

Soil PH:                       6.0 – 6.5        
Soil Type:                    Loose and well drained
Planting Season:          3 to 4 weeks before the last frost date, mainly January
Planting Depth:            3/4 in
Plant Spacing:             3 to 4 in
Row Spacing:               4 in    
Plant Height:                18 in
Days to Germinate:      3
Sun:                            Full
Days to Harvest:          120 to 150

Plant Characteristics
Onions grow up to 18 inches tall. The bulbs form underground.

When to Plant
Onions love cold weather with full sun. You will not get good top growth without some cool days. Plant Onions 3 to 4 weeks before the last frost date. For most parts of the northern hemisphere, onions can be planted in January. Onions are a cool climate plant and thrive in the cold. If you plant too late, your yield will be greatly hampered.

Soil Preparation
Choose a site that receives full Sun and has well drained soil. The soil should receive at least 6 hours of Sun. Onions like loose soil for up to at least 8 inches deep. Add a lot of compost and 10-10-10 fertilizer to your soil. A soil pH of 6.0 to 6.5 is ideal for growing Onions. Apply lime and fertilize according to soil test results.

Good Neighbors of Onions are Beets, Cabbage, Carrots, Celery, Cucumber, Lettuce, Pepper, Squash, Strawberries, and Tomato. Bad Neighbors include Bush Beans, Pole Beans, Peas.

Do not plant onions in the same soil for more than one season. Rotate the crops to various sections of your garden from season to season. Onions need plenty of water, so choose an area where water is readily available.

Planting
Smallest onion bulb yields the larges onion. Sort sets into two categories, one larger than a dime and other smaller. Plant the larger sets for green onions and plant the smaller ones with adequate spacing: they'll produce bigger onions. Pick out the best and healthy bulbs and plant onion sets, pointy end up, ¾” to 1" below soil. Space Onions 2” to 3” apart if planting for green Onions and 3” to 4” inches apart if planting for full size Onions.

Caring
Watering is critical when growing Onions. Water slowly and deeply to produce healthy Onions. Onions should receive about an inch of water every week.

Once the plants are leafing out, fertilize using nitrogen rich fertilizer. Scatter the fertilizer evenly between the rows. Continue to apply a 10-10-10 fertilizer every 2 weeks.

Onions do not have many insect problems, but thrips (a very small yellow or black insect) may be found on the inner leaves. Use insecticidal soap or other labeled insecticides for control (follow label directions, especially for last application prior to harvest).

When an onion sends up a flower stalk, pull the onion and use it; it will not continue to grow larger nor will it store well.

Harvesting
If you plant Onions in January, they will be ready to harvest in May or early June. Onions are edible at any stage. Immature bulb-forming onions can be thinned from the garden and eaten.

Onions are ripe when ¼ to ½ of the tops have fallen over and bulbs have developed a papery skin. 50% or more to the tops should have fallen over for storage onions. Onions will store better if they are dried for several days outdoors, away from direct sunlight. Pull the Onions, and keep them outside for 5 to 7 days for drying. Leave the tops on the bulbs during drying. After drying, cut tops within an inch of bulb and store in a cool dry place until needed.

Mature, cured onions are physiologically dormant. The length of dormancy depends on what cultivar you've planted. Cool storage will prolong dormancy. The recommended storage temperature is 32 degrees. Do not let them freeze. Onions will start to sprout at temperatures over 40 degrees.

Subsequent Crops
It’s best to buy bulbs from your local grocery store or nursery for planting Onions in the next season.