All you wanted to know about onions

Sunday, June 17, 2012

Onions with white flower tops

The onions we cultivate today likely originated from a wild Asian onion, but has been grown so long, its road back to the original is lost.

Two thousand years ago, there were many varieties that we would recognize today.  There were round onions, white onions, red onions, flat onions, long onions, keeper onions, sweet onions, spicy onions.

Onions have been important for their perceived health benefits in times gone past and proven today.

There are wild Alliums in America as well known as wild garlic or ramp.  

Onions have shallow roots, like to be moist, but can’t stand being waterlogged, and hang out in fertile soil.  Seeds can be sown in the fall, October in our area.  The more popular method is “sets” that are young onions that are put out in early spring as soon as the soil can be worked, just as the daffodils begin to fade.

Close up of white onion flower

You can place them close together and pull for scallions until the bulbing onions are 5-6” apart.  As the bulb reaches full size, you can pull the soil away from the top of the onion to help the bulb and neck cure for harvest.  

You can also plant the bottoms of store bought onions.  If you get enough of the bottom, the onion will take root and give you an onion next season.

Onions tell you when they are ready to harvest, when half of their tops fall over.  What can be easier than that?  Like garlic, they should be lifted rather than pulled from the ground and leave them in shade for about a week to harden.  I use a trowel to dig under the bulb and pop them out.  You don’t want to knick them or they will not store well.  If you do, keep them in the fridge and use them first.

So, how do you choose which onions to plant?  The best bet is to talk to your local nursery to see which grow the best in your area.  If you live in the northern part of the country, you need long day onions.  If you live in the south, you need short day onions.  Onions are sensitive to day length.  It is the amount of daylight that triggers the bulb to form.  So, you need to get the right type of onion for your daylight hours in the summer.

So, if you want a sweet onion and live in the Midwest, Vidalias are not the best bet since it is a short day type.  A better choice is a Walla Walla or a Sweet Spanish.

The other thing to keep in mind is that, like wine, onions pick up the terroir they are grown in.  You can grow the exact same onion as another, but have a different taste because of the differences in your soil.

There are many fun onions to grow besides the round ones.  There are the flat disk like Borrettana Cipollini or the Red Baron onion that is a red scallion type onion.  Of course, there is the onion made famous in French cooking, the shallot-French, Gray or Sante are well known varieties.

Then, there are onions for keeping over the winter like Rossa Di Milano, Early Yellow Globe, Sweet Sandwich, and Granex Yellow.

Onions will also keep over another year.  When onions I planted last spring did not get to decent size, I left them over the winter.  They are bulbing up quite nicely this summer.

Close up of bulblets

Another type of onion is the Egyptian walking onion.  It is a perennial that you can pull year round.  They do not form bulbs.  They are like a very large scallion, getting an inch or two wide and 3” long bulb.  They also grow great in a pot.  When they get their bulblets, they remind me of Medusa.  Really cool.

Egyptian onions in a pot