Most home gardens are global melting pots of tasty veggies, but each has but one or two names in any given language. In English, eggplant = aubergine and squash = marrow, but tender green onions (Allium fistulosum) may be called scallions, Welsh onions, spring onions, salad onions, Japanese bunching onions, and the list goes on. Shall we clear up some word confusion?
"Scallion" sounds French, but scallion evolved from the name of a town in Israel where an enterprising gardener began growing these strange onions from the Far East many centuries ago.
"Welsh onion" can be traced not to Wales, but to the pre-German word walhaz, likely coined by ancient Northern Europeans to describe all things Roman, including their onions.
"Spring onion" takes us into the muddy waters of onion history, which once included many more perennial onions, especially potato or nest onions. Cutting off a few tender shanks here and there didn’t hurt productivity and provided tasty pickings in late spring, a hungry time of year. Spring onion also is an appropriate descriptor for any onion sown from seed in fall or late winter that grows with vigour as soon as spring days get longer and warmer. Young onions pulled and eaten as the bed is thinned may be bulb onions at heart, but they are eaten as green onions.
These days the market versions of green onions are mostly variations of Allium fistulosum, a non-bulbing, bunch-forming onion species that probably originated in China. In the early days of civilisation, while Europeans were selecting Allium cepa for big bulbs, Asian gardeners were selecting bunching onions for vigour, flavour, and ability to propagate themselves by seed and by division. This 1943 British Council Film explains the onion life cycle better than I can, the only footnote being that overwintered bunching onions produce seeds just like bulb onions do. They are also likely to multiply by division, with single plants dividing into two or three separate shanks twice a year, in spring and fall.
Growing Green Onions
It is fortunate that most commercially grown green onions are of the Japanese bunching type, because you can buy a bunch that show good roots, trim them back by half their size, and plant them in your garden or in a container. Then pull them as you need them in the kitchen, but save the rooted bottoms and replant them. Simply cut off the bottom inch (3 cm) of your green onions and plant them in damp soil, or keep them in a jar of water in a sunny spot. A second harvest of onion greens will be ready in a week or so, after which the onions can be composted. This trick works great with bunching onions, but is much less dependable with onions that form bulbs.
As the soil warms in spring, you can plant green onions grown from seed sown into finely cultivated beds. Covering the soil's surface with a blanket of weed-free potting soil can reduce weeding in the first few weeks, but the little plants still will need you to pull out weeds as they gain a foothold. You can also start seeds indoors and set out the seedlings when they have three leaves, but most gardeners (including me) save labour-intensive indoor seed starting for onions that grow into big bulbs.
If you want the sweetest green onions possible, start with a proven variety like Guardsman or Ishikura and target your harvest so you pull most plants when they are 10 to 12 weeks old – the zenith for leaf sugars in onions. To insure a good supply into autumn, start a second run of seeds in midsummer.
Whether you sprinkle them over egg drop soup or mix them into cold salads, green onions have high levels of vitamins A and C and calcium along with compounds that promote heart health and may help prevent cancer. These health benefits are found in other onions, too, but pungent alliums must be cooked to be edible. Whether you call them spring onions or welsh onions or whatever, green onions are mild enough to eat raw, with all of their health-promoting properties intact. Because of this, they may be the most nutritious onions you can grow.
By Barbara Pleasant