Popular Varieties: Red Baron, Setton, Bedfordshire Wonder
Store At: Cool, dry place with good air circulation, away from bright light. Don’t refrigerate them.
Comes From: Worldwide, usually temperate regions
Seasonality: All Year Round
The flavour of onions varies between types and varieties; typically, large Spanish and red onions are milder, but this is only a general rule. Others have been bred for better hardiness, colour or disease resistance.
So why do onions make you cry? The cells within the tissue of the onion have two sections; one containing enzymes called allianases, the other containing chemicals called sulphides. When the onion is sliced, these cells are broken, and the two chemicals react, with the enzymes breaking down the sulphides and generating sulphenic acids. These are unstable and quickly break down into a gas called syn-propanethial-S-oxide. Still with us? Good! This gas gradually moves through the air and when it reaches the eye, it reacts with the water on the eye and forms a mild sulphuric acid solution, which naturally irritates the nerve endings in the eye, stimulating the tear ducts to produce tears to wash it away.
Various tips exist for assisting you in cutting them; the easiest method is goggles, although other methods include cutting them underwater or freezing them for a short time first; people have even gone so far as to breed an onion that doesn't cause as many tears when cutting.
Shallots are also included here; they are better for colder climates than onions, since they grow faster and mature rapidly, and will also grow on poorer soils than typical onions. Shallots are a smaller version of onions, typically used for cooking purposes, and usually have a milder taste than onions, hence their popularity.
History
It's difficult to determine the exact origin of onions; their tissues are soft and leave no historical trace. Some botanists believe they originated in Central Asia, whilst others believe they came from Iran and Pakistan; however they all agree that onions were cultivated before pre-history, for 5,000 years or more. They were probably cultivated simultaneously in many regions, and because of their excellent storage, ease of transport and ability to grow in so many climates meant they were probably a staple part of the diet.
In some countries, the onion became more than just food. In Egypt, onions date back to 3,500 BC, when they were worshipped, people believing that the concentric rings and spherical shape symbolised eternity. They were strongly aligned with kings, appearing in tombs and used during the funerals and even the mummification processes. They even went so far as to make images of them out of gold! In Ancient Greece, athletes ate lots of onions because of its ability to thin the blood.
Onions have been recorded as growing in China as far back as 5,000 BC, and Ancient Sumeria in 2,500 BC. The Romans believed them to have great medicinal uses, in curing poor vision, inducing sleep, curing mouth ulcers, dysentery, lumbago and more.
In Europe in the middle ages, onions were part of the staple diet, along with beans and cabbage and once again they were used for many medicinal purposes.
The Pilgrims took onions to America on the Mayflower; although Christopher Columbus first introduced it to North America on his 1493 expedition to Haiti; even though wild onion strains were already growing in America, and were already used for a large variety of purposes, such as cooking, eating raw or seasoning amongst others.
Uses
Today we use onions for culinary purposes more than anything; Spanish onions or red onions are typically used in salads because of their milder flavour; or for any other purpose if you don't like strong onions! Yellow and white onions are used in cooking, be it fried, baked, roasted… you can do pretty much anything with; you can even boil them to make creamed onions!
Shallots are typically used in cooking too; they generally have a milder flavour.
Onions are also used for medicinal purposes; they appear to have some effectiveness against colds, heart disease, osteoporosis, diabetes, and other diseases. They also contain anti-inflammatory, anti-cholesterol, anti-cancer compounds, and antioxidants such as quercetin. In other parts of the world they are also used to treat blisters, boils and scars.
And finally, let's not forget ornamental; if you let an onion run to seed, the flower that precedes the seeds is very decorative.
Growing Information
Onions can be grown by one of two methods; seeds or sets.
Growing onions from sets is the easiest method by far, and is possibly one of the easiest methods to grow any type of vegetable. Sets are small onions, which are purchased and planted from February to April. They must be planted with just the very tip protruding from the soil; from here, they will sprout, and grow into bigger onions, when they are then harvested. Easy!
If you want to grow onions from seed, there are two methods. The first takes two years. In the first year, you scatter onion seed thickly, and allow them to grow. The resulting bulbs are small, much like sets, and can then be planted in a similar method to sets the following year, and grown on. Onions grown this way however are not as durable as those sown less thickly and the resulting seedlings thinned out, and then grown on to full size.
Either way, it’s pretty easy – plant them, water them if they get too dry, and that’s pretty much it. Onions can get attacked by the onion fly, although there is some evidence to suggest that companion planting may help; if carrots are planted next to onions, the carrots can help prevent onion fly from attacking the onions, and vice versa; the onions help prevent carrot fly attacking the carrots.
Links
- Onions Portal
- Onions on Wikipedia
Varieties
Different varieties of onions are used for different purposes, from red onions such as Red Baron for salads, Setton for general use including cooking, and shallots such as Atlantic when a milder taste is required for cooking.
Sturon
A traditional variety which has won the RHS Award of Garden Merit, this is a medium sized bulb that stores well.
Ailsa Craig
A classic variety favoured by many, this is a large onion, round, with straw-coloured shell and a mild flavour.
Atlantic
Atlantic is a shallot, an early variety to be more exact, which produces heavy yields of a medium to large bulb which store well and are very tasty.
Red Baron
A strong flavoured variety, Red Baron is a red coloured type that is very eyecatching, with red shells covering each ring of flesh.
Senshyu
Slightly different to most other varieties we have discussed here, Senshyu is an overwintering Japanese onion with a semi-flat shape and yellow-brown skin.
Setton
A uniformly shaped good yielding onion with good storage ability, this is a refinement of the Sturon variety, and has won the RHS Award of Garden Merit.