Easy-to-grow vegetables that are ready to harvest in just eight weeks make spring onions a firm favourite. Perfect for use as a "filler crop" between rows of slower growing vegetables, this tasty salad and stir-fry staple can be eaten raw or cooked. Here’s how to grow spring onions from seed.
Spring onions add interest to many dishes. The white bulbs have a delicate oniony flavour while the long hollow leaves can be thinly sliced to add texture and colour.
The benefit to growing your own spring onions from seed is that you can try varieties not readily available in the supermarket. Choose from solid all-rounders or those best suited to pickling or growing over the winter. Here are some of our favourites:
Sow spring onion seeds from March to August at 3 weekly intervals. Harvesting can usually start 8 weeks after sowing.
For an early spring crop, sow seeds in September and over winter.
Spring onions will grow in any good fertile soil provided it’s well drained. Prepare the ground in advance by getting your soil down to a fine tilth and adding a granular general purpose fertiliser about a week before you expect to sow.
Make drills 1.5cm (0.5") deep and 15cm (6") apart and sow thinly. You won’t need to thin your spring onions because you’ll be pulling them and adding them to your salads in just a few weeks.
Spring onions rot in waterlogged soil, so do plant them in well-drained ground, and be careful not to over-water. It’s also crucial to keep weeds away because like all onions, spring onions hate competition. It’s also advisable to protect the young seedlings from birds, by covering them with horticultural fleece.
You can also sow spring onions into containers or pots on the windowsill. Just add compost to within about 3 cm (1") from the top of the container before lightly scattering seed over the surface and covering with 1.5cm (0.5") of compost. Water sparingly to keep the soil moist and you’ll soon have a tasty crop to enjoy.
Small bulbs are ideal for salads and stir-fries, but some varieties develop into larger, normal-sized onions if you leave them long enough. Do beware of "bolting" in hot weather – snip out any flowering heads as soon as they appear or, though still edible, your onions will be smaller.
Spring onions also overwinter well. By sowing them in late August, through to October you’ll get a nice early crop of crisp salad veg by the end of spring.
Now you know how to grow spring onions, why not give them a go? Versatile, delicious, and highly nutritious, these crisp, crunchy scallions really are a must for your garden. Find other popular alliums to grow, growers guides, and our full range of products at our onions, garlic and shallots hub page.
Plants and gardens have always been a big part of my life. I can remember helping my Dad to prick out seedlings, even before I could see over the top of the potting bench. As an adult, I trained at Writtle College where I received my degree, BSc. (Hons) Horticulture. After working in a specialist plantsman's nursery, and later, as a consulting arboriculturalist, I joined Thompson & Morgan in 2008. Initially looking after the grounds and coordinating the plant trials, I now support the web team offering horticultural advice online.
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