Chances are you’ve already tasted a Welsh onion, though you might not have recognized the name at the time. These bright green veggies are also known as bunching onions, Japanese bunching onions, spring onions, and long green onions. They’re easy to grow, incredibly versatile, and bring a bright sharpness to every dish they’re added to. Read on to learn how to cultivate your own!
What is a Welsh Onion?
Tender, green onions are known by many names. Whether you call them scallions, spring onions, or Welsh onions, these easy to grow members of the the Allium family provide a reliable source of flavor throughout the growing season.
The Welsh onion is a bunching onion that can harvested gradually like chives, pulled up whole, like bulbing onions, or both!
Despite their name, Welsh onions aren’t native to Wales. The name probably derives from the ancient Germanic word walhaz—referring to anything commonly used in Rome. The truth is, bunching onions are common in many areas of the world.
Some people have a passion for onions. The love them roasted and spread on toast, or speared onto kebabs with peppers and squash. Since onions come in all shapes and sizes, those of us obsessed with green onion cream cheese or scallion and cheddar biscuits try to fill our gardens with all the varieties we can find.
Welsh onions (Allium fistulosum), are an ideal option for extending your onion season. These chive-like bunching onions offer and easy and consistent vegetables for your table.
There are so many varieties to chose from. Many of the best varieties come from Japan, and Welsh onions are often called Japanese bunching onions because of that.
A delicious, consistent, Japanese variety of Welsh Onion, Ishikura is a sweet and flavorful variety. If you have onion-wary guests, serve Ishikura bunching onions. You’re sure to delight everyone.
Red Welsh Bunching
This cold-hardy variety hails from Siberia, and produces thick, green stems with a strong, sharp flavor. Not for the faint of heart, red Welsh onions are amazing on top of smoked salmon sandwiches.
Large, flavorful, and easy to grow, Negi will being to grow like overgrown chives if left to their own devices. This variety thrives on neglect, and is perfect for low-maintenance gardens.
This variety is known for its beautiful, straight stalk and mild, accessible flavor. The Southport improved is also more resistant to fungus than other varieties. If you live in a damp climate, this might be the ideal bunching onion for you.
Sun and Soil
Welsh onions are not picky plants. They grow best in moderate to rich soil, heavy in phosphorus, but unless your soil is very poor, your plants should thrive without added nutrients. Bunching onions are happiest in full sun, but they grow happily in dappled sunlight or partial shade as well.
Give your bunching onions decent soil, plenty of sun, and consistent moisture. But don’t worry too much. Bunching onions are hardy and self-sufficient little plants. I like to plant mine in sunny window boxes because they look so pretty and slender.
Try to make sure that the soil you start them in is free of grass before you plant. Young bunching onions look almost exactly like grass, and it’s hard to weed when everything looks the same.
Start your spring onion seeds indoors about 4-5 weeks before your last expected frost. You can plant multiple seeds in a common pot and just separate them at transplant time, or you can plant one or two seeds in a small pot.
Plant your seeds just below the surface of the soil and cover with a thin layer of dirt. When your seedlings start popping out, keep them well watered and give them plenty of sunlight. Onion roots are shallow, especially as seedlings, so be sure to keep these little guys hydrated.
It’s a good idea to apply a light amount of bone meal or other phosphorus-heavy fertilizer before planting. This will give your Welsh onions a healthy start in light and help them grow thick and flavorful.
Once any danger of frost is past, you can transplant your seedlings outside. Give each individual plant its own spot in the garden. Don’t force your Welsh onions to compete with weeds or each other: they’re not competitive plants.
Tending Welsh Onion Plants
Once they’ve started growing, your bunching onions need very little upkeep. Weed and water consistently, but otherwise just let your little onions grow.
Welsh onions do best when they’re consistently weeded. Weeds can crowd out these types of onions and make it difficult for you to find them at harvest time. Weeds will also steal valuable nutrients from your little greens.
If you wait too long to weed your scallion bed, the shallow-rooted onions may be accidentally pulled up along with the weeds. So weed your onions while the interlopers are still small and easy to remove.
Give Welsh onions a thorough watering and then let the soil dry until it’s just slightly cool and moist before watering again. As much as they love regular irrigation, established Welsh onions are relatively drought hardy. If you miss a few waterings, they’ll forgive you!
Pests and Diseases
Have you ever noticed just how few pests attack onions and garlic? Their strong scent tends to keep away many would-be intruders. But there are always a few that manage to sneak in and plague every plant. Bunching onions may not have many pests, but they do have persistent ones.
These tiny monsters are almost impossible to spot, but you’ll definitely see the damage they leave behind. Look for silvery streaks and white blotches on your onions, and you’ll know you have a thrip problem. Fortunately, thrips are soft-bodied insects, vulnerable to insecticidal soap.
Spray affected plants consistently until all signs of thrips are gone.
Nematodes and Onion Maggots
Is there anything more disheartening than losing your beautiful onions to maggots? Onion maggots and nematodes attack the plant at its root. Even bulb-less varieties like Welsh onions are at risk. These pests fill the roots with tiny tunnels, causing it to rot.
When these pests strike, pull up your onions and use what you can of the greens. There’s no way to save your crop. But, you can prevent them by rotating your onion beds. Don’t grow your onions in the same place each year: rotate all your crops annually.
If you’ve grown leeks or scallions in a bed one year, grow something entirely different the next year. Plant your bunching onions in an old bean bed, or last-year’s pepper bed. Confuse those pests as much as possible!
Along with the persistent pests, Welsh onions are sometimes plagued by fungal diseases. The best way to prevent fungal issues is by keeping your garden clean and healthy. Weed out crowded plants so the sunlight can keep your onions warm and dry. And if fungal diseases tend to be an issue, the your soil and onions with garlic or oregano tea occasionally.
Oregano is an anti-fungal and can help your onions fight off fungal spores. Spray on warm, sunny days to help the plants dry off quickly and keep pockets of moisture from forming.
Garlic and garlic are often grown together as companion plants for beets, peppers and tomatoes. The scent of onions is often enough to drive away many of the pests that bother these plants.
Chamomile is a helpful companion plant for bunching onions because it’s an all-round garden booster. This herb drives away pests, boosts flavor, and keeps it’s companions in the garden content.
Onions are also often grown with herbs such as parsley, oregano, thyme, and savory. Many of these herbs also help reduce issues with fungal diseases and drive away pests.
Harvesting and Using
You can harvest Welsh onion tips all through the growing season. Treat them like oversized chives and snip off the tips as they grow. I love using scallion tips in breads, biscuits, and casseroles. They’re also the best onions to top soups and chilis.
You can continue to snip the green tips as they grow back. It’s a great way to add onions to your spring and summer menu!
After about 12 weeks of growth, harvest the entire plant by pulling it up from the soil. Wash your Welsh onions and use the whole plant—chopped—in curry or on pizzas. Pickled green onions are delicious on sourdough sandwiches. Creamy Welsh onion soup is another delicious, autumnal option.
Welsh onions don’t store as well as conventional onions, so use them while you can. They will last in the refrigerator for up to a month though. Keep them in the crisper and don’t wrap them in plastic. Allow your green onions to breathe a bit. You can also keep them in a root cellar for almost a month, thought the green tips will wilt after a week or so.
An Onion for All Seasons
If you just can’t wait for a late summer onion harvest, give Welsh onions a try. Bunching onions are a great way to enjoy both the oniony green tips and the more intense, root flavor. They’re an easy, consistent plant and an ideal introduction to growing onions for gardeners who want to get started growing onions.
Every onion lover should give flavorful, bunching onions a try. You’ll find they quickly become an essential part of your summer garden!