Green onions are easy to grow and are harvested in Ontario from June until November. Scallions is another name for the green onion, it may be a earlier harvest then the green onions, but it is debatable as to whether there is a difference.
Green onions are immature onions with a much milder flavour than fully-grown onions.
They are easy to grow if you want to grow your own. Plant the organic or heirloom or naturally grown onion seed in a pot filled with a soil-less medium, like an organic or natural seeding mix, and place the onion seed about 2 centimetres into the soil. Keep seeds about 6 centimetres apart.
Make sure to keep the soil moist, do not let it dry out. You can transplant outside after May 24 or last frost date.
Use green onions raw in salads or to garnish platters, dips and soups, or use them as a popular stir-fry ingredient along with other vegetables.
On the grill, cook them whole and serve with steak.
Green onions are great with omelettes, egg salad, potato salad, most green tossed salads, I also use them in sandwiches, homemade bruschetta, tuna melts, and much more.


You can start red onions from seed but planting from red onion sets, or red onion bulbs, will let the plants reach maturity more quickly than plants started from seeds.
If you do start from seed use a soil-less medium and plant the seed about ¼” deep. Keep the plant damp, like a wrung out sponge, at all times. Keep it covered until the first sprouts appear. Then move it to a sunny spot.
Soil Preparation
Onions require well-drained soil rich in organic matter. Make sure the plants do not dry out. Water as they need it. They also need six to eight hours of direct sunlight daily.
If your garden site drains poorly, it would be advised to create a raised garden bed, which will improve drainage. It is especially a good idea for red oinions as they need to be kept moist. Also additional compost helps to improve moisture retention in sites that drain too quickly.
Prepare their garden bed for planting with a 1 ½ to 2-inch layer of compost into the top 5 inches of the soil. When you add the compost it removes the need for fertilizing later; the nutrients in the compost will sufficiently feed the growing onion plants.

Planting Procedure
Since size determines the best use for red onion sets, sets larger than 1 ½ inches in diameter are best used for growing green onions. They flower earlier than other sizes and flowering stops bulb growth.
Larger sets are more likely to produce a large, red onion bulb. Push the sets into the soil so their pointed tips are just above the soil surface.
Space the sets 2 inches apart for green onions or 5 inches apart for red onion bulbs.
Space rows 12 to 18 inches apart so you'll have room to weed the soil and access the onion plants.

Red onions require minimal care once they are planted, other than regular irrigation. Pull weeds regularly so they don't compete with the onions. Water onions once or twice weekly, or when the top 3 to 6 inches of soil begins to dry.
Onions need about 1 inch of water per week from either rainfall or irrigation. Over watering can result in bulb rot or fungus problems. Be sure to check the soil moisture before watering, so it does not become soggy or waterlogged.

Red onions grown for bulbs usually require three to four months to reach maturity. Reduce watering when the foliage begins to yellow. Bend down the foliage after it begins to fall over. This will speed up the onions' maturity.
Dig up the onions about two weeks after you have bent the foliage. Loosen the soil on each side of the onion row, and lift the bulbs from the soil, don't pull them up by the leaves. After removing the bulbs' leaves and roots, allow the bulbs to dry in a shaded location for two weeks before storing them.


When to Harvest

When onions have stopped growing the leaves will lose their color, weaken and flop over. Don’t fret when you see the leaves at the top of the bulb die out. This means that the onions are ready to harvest.
Once the leaves have fallen down, leave the bulbs in the ground for about another two weeks to mature fully. Don’t leave the onions in the ground for much longer after the tops die or they could become open to rot and other problems.
Pull your onions up on a sunny day and let them dry out in the sun. The drying kills the root system at the bottom of each bulb. Sun dry for just a short time.
Picking the right day to pull the onions can determine how well the onions will keep. The best time is on a nice sunny day and not in rainy weather. They'll dry out a lot faster if they are dry when you pull them up.
To cure the onions, spread them out in any warm, airy place out of the sun, if you have racks or potting benches, or a shaded patio, anywhere you have space to lay them out. Turn the bulbs a couple of times to promote even drying.
Storing the onions
After drying the onions in the open for a day or so, it's time to bring them under cover for a second, longer drying process. Cure just the onions you'll store and separate the soft, young and thick-necked bulbs and use them first.
So it is important to cure them thoroughly in a warm, well-ventilated area away from direct sun. Don't crowd the onions during this curing; give them a bit of room to breathe.
Cover them with sheets or netting, or shade cloth.
You don't want any wet spots on the onions when you put them in storage, so make sure they have dried really well. This can take two to three weeks.
After drying or curing the onions, hang the onions in mesh bags in your garage or an outbuilding or shed to dry them some more before putting them in your root cellar. The longer you cure your onions, the better they'll keep. Onions are ready to store when the skins rattle and the roots look dry and wiry.

Onions are ready to store when the skins rattle and the roots are dry and wiry.
Onions can be picked and eaten at any stage. I always want to have a nice crop of big mature onions, red and yellow, at the end of summer. You can use them right through the fall and winter months.