How to grow your own spring onions

Despite their name, spring onions are great growers year round but they’re ideal for this tricky time in the garden.

By Mat Pember
Despite their name, spring onions are great growers year round, writes Mat Pember, but they're ideal for this tricky time in the garden.
The back of winter has been broken and spring is awakening. Think of September as the season's morning - as though it's just out of bed and yet to have coffee, spring is erratic, temperamental, and frankly a pain in the patch. Spring may be here, but not yet in all its glory.
Gardening purists, and anyone else who keeps an arbitrary track of time, argue that spring really takes hold in October, with this month more of a prelude. It's when we make the mental shift, rather than a physical one. But spring is also empowering. We've arrived. Kind of.
This month we profile a spring classic: hardy, fast-growing, and versatile in the kitchen, spring onions tick enough boxes to have you coming back for more. And that could be at any time of year - the spring onion could easily be named the autumn, winter and summer onion, too.
Although not overly fussy about their growing conditions, spring onions appreciate some basic requirements being met. And the better you can satisfy these needs, the better they'll grow. They will tolerate partially shaded spaces, for instance, but they thrive in sunny positions in a free-draining soil.
Before planting spring onions, prepare your patch with compost and slow-release chook manure. This should supply the spring onions with enough nutrition for the whole growing journey, which lasts anywhere from one to three months, depending on how you harvest (more on that later). Like with most vegetables, however, a fortnightly tonic of liquid seaweed extract will supplement your efforts that extra bit.
When planting from seed, form shallow trenches with the tip of your finger, spaced about five centimetres apart. The seeds are minuscule, so trickle them along the trenches every few centimetres. Inevitably some thinning will be required once the seedlings are large enough to handle.
Keep the patch damp but don't overdo it - too much water can dislodge the seeds and send them floating to an early demise. Juggle your watering routine with whatever rainfall spring throws up. This is one of the areas where the season can be erratic - it's statistically one of our wettest.
When you plant seedlings - our preferred method since they're so easy to transplant - you'll find spring onions show real grit and hardiness. Here, make a trench a few centimetres wide and a few deep and lay all the seedlings along the line, spaced three to five centimetres apart, with the root zones in the trench. Cover the roots with soil and water them in, with the seedlings still laid out flat. While it may seem awkward for the spring onions to be planted horizontally, after a day or two of water and light, they quickly find their feet.
Water the seedlings two to three times a week; more frequently if you're growing them in pots or when the weather heats up. After a month, your vertically challenged seedlings will be standing tall and proud, nearly all grown up. You can now start harvesting as you choose.
Rather than rip out the entire plant, roots and all, the sensible approach is to cut off the stems, leaving the hardy root zone in the ground, which means they can immediately refocus their efforts to growing another round of spring onions. This method of harvesting can be repeated until the plant becomes unpalatable - usually at the point when slime rather than water fills the inner core of the onion. At that point, remove the entire plant and move on to your next spring fling.
Harvesting techniques are normally taken for granted, but the way you pinch, cut, pull, rip, pick or plough the produce from your patch can affect it on many levels. It's the difference between sensible and overeager harvesting, and you learn what suits different crops best with experience and many mistakes along the way.
No one would imagine there'd be much in common between mushrooms and spring onions (other than good chemistry in the kitchen), but when it comes to harvesting, similar principles apply to both. Rather than ripping them out entirely, it's best to cut both spring onions and mushrooms at the base of the stem. This allows the plant to regenerate and extra flushes of produce will follow from the root zone that remains. The plant will re-shoot and be ready to go again in no time.
It makes sense to harvest this way when you can so you're not starting from scratch over and over again - you've got a head start on the next offering.
Illustration Tom Bingham