Introduction to Growing Onions
Onions are a great pick for the home gardener. They grow well in most parts of the U.S. and have many uses in the kitchen. You can grow them specifically for green onions or you can let them mature and harvest them for their large bulbs. You can also choose to grow onions and use a few early as green onions, harvesting the remainder as delicious bulb onions.
There are also special kinds of onions that don’t develop bulbs and that are used exclusively for green onions. Onions are a popular cool season vegetable and although they are considered a biennial plant they are grown as annuals.
The onion is exceptional in that it will thrive under a very wide range of climatic and soil conditions. There is perhaps no extended area in the United States, except for the mountainous regions, where the onion cannot be successfully grown. However, onions grow best in temperate climates without great extremes of heat and cold.
Onions grow in an unusual manner. They start growing the large bulbs we know as onions when the levels of daylight reach an appropriate level for them to start forming. The time that you plant the onions affects when they form bulbs. If you plant your onions too late in the season, they may not form bulbs properly.
One important thing to remember about onions is that there are two different classes: long-day and short-day onions. Long-day onions are more appropriate for northern states because they are adapted to longer days. Southern states should use short-day varieties of onions. When you go to your nursery, they will usually list long-day onions as L and short-day onions as S. Short day onions develop bulbs with an average of about 12 hours of daylight. Long-day onions form bulbs with more sun, around 15-16 hours of daylight. You should grow the kind of onion appropriate for your region to ensure proper maturation of the onion bulbs. Keep reading for more information about long-day and short-day onions.
Shallots are related to onions but have a different flavor. They also have ornamental value as they produce attractive flowers during the summer. They can grow quite tall as well, about 1 ½ feet. French shallots (grey shallots) are quite popular. There are also red shallots, echalion shallots, and Dutch yellow shallots.
Recommended Varieties for Green Onions
White Portugal onions are a great pick to make green onions. Other varieties for green onions include White Spear, Ebenezer, and Tokyo Long White.
These kinds of onions are appropriate for harvesting as green onions. Recommended varieties include Beltsville Bunching and Japanese Bunching. These onions work just as well if planted from seedlings, seeds, or sets. These kinds of onions are a good pick for colder climates and late fall to winter harvests. They will not form bulbs and indeed the entire plant with the root structure can be harvested and used.
These are onions that are planted during the winter in some areas and are harvested during the following growing season. Egyptian, Hill and Walking Onions are often considered winter onions. They are good for an early batch of green onions. Make sure to use a layer of mulch with these kinds of onions. Cornell University has a great guide to growing Egyptian onions.
‘Texas Grano 1015Y’ has good disease resistance. Crystal Wax is a disease resistant white onion with a mild flavor. Use quickly after harvest.
Out of all the onion varieties out there, the white Bermuda onions keep about the least amount of time in storage. You can easily grow the white Portugal from seed. Use this onion quickly after harvest.
Pungent yellow onions are the onions that work best for long storage. Yellow Globe and Copra are good picks for a long-storing yellow onion. Sweet Sandwich is a yellow hybrid onion that stores well. It grows as a long-day variety.
The large red onions are usually sweeter onions. They are good for eating raw or cooking. Burgundy is a delicious red onion. It has a milder flavor than other onions. Red Wethersfield is a good pick and comes as a long-day onion. This onion grows very well from sets.
Sweet onions are sometimes larger than their smaller cousins. Vidalia, Sweet Spanish, Bermuda, and Walla Walla are good picks for sweeter onions. The white Bermuda has a great sweet taste but won’t keep for long in storage.