How to grow spring onions

Growing spring onions in Perth

Spring onions are vegetables derived from various species in the genus Allium. Spring onions have a milder taste than most onions. Their close relatives include garlic, shallot, leek, chive, and Chinese onions. Spring onions are a wonderful addition to a number of foods providing a crisp and crunchy mild onion flavour to salads, stir fries and other dishes.

If you have ever wondered how to grow spring onions in Perth then look no further. Spring onions are an easy vegetable to grow at home, although there are a few tricks to successfully growing spring onions in Perth, Western Australia. Get these right and you will be laughing.

When to plant spring onions in Perth:
Spring onions can technically be planted all year round here in Western Australia, however If you’re planting them during the hottest or coldest months, they’ll need a little extra attention.

Spring onions can be grown from seeds, seedlings or even scraps from old plants.

Where do spring onions grow best?
The ideal growing conditions for spring onions is a sunny spot with moist, well-drained soil. They like the soil to be slightly acidic (pH 5–6) but aren’t too fussy and can grow in soils up to pH 7. Add a small amount of bonemeal into each hole before planting if unsure.

How much water do spring onions need?
Spring onions have a relatively small root systems so the soil must be kept moist. One daily watering in early morning is sufficient from April to October with twice daily watering, in early morning and early afternoon, needed in the hotter months from November to March.

Are spring onions a perennial?
Yes, whilst spring onions are often grown as an annual, they are in fact a biennial, producing a flower and seeds in their second year.

Types of spring onions in Australia:
There are a number of spring onions varieties available in Australia, they are usually varieties of bulb forming onions which are harvested early, before the plant has had a chance to form a full onion bulb.

Spring Onion Straight leaf – This variety holds its stem and leaves straight upwards which means the plants are tidier and less prone to disease.

How to grow spring onions from seed:
Growing spring onions from seeds is easy, fun and rewarding! In general growing spring onions in pots is a great idea. Below are the steps on how to how to grow spring onions in a pot from seeds.

  1. Choose small or large pots. Position in full sun and fill with quality potting mix.
  2. Place few spring onion seeds in each pot depending on the size of the pot and cover them with the potting mix to about 6 mm deep.
  3. Water in well with a rose head fitted watering can.
  4. Once germinated keep them well watered, but avoid keeping the potting mix too wet.
  5. Feed your spring onions a liquid plant food every few weeks to promote foliage growth.
  6. Harvest them after 8 to 10 weeks by pulling out the entire plant by holding it at the base of the stem near the ground.

How to grow spring onions from cuttings:
What a lot of people don’t realise is that you can grow spring onions from scraps. Spring onions sold with a root end that you always trim off before using the green stalks in almost all cases. But the amazing thing is you can actually regrow new spring onions with the those bulbs. This means you can almost create an endless supply of fresh spring onions from kitchen scraps. All you need is a starter bunch of spring onions, a jar, and fresh water.

  • Slice off the ends of the bulbs, leaving thin dangling roots attached.
  • Stand the bulbs root-end down in a small jar. Add enough water to cover the roots, but leave the tops above water.
  • Set on a windowsill and keep the roots moist. After a few days, you should start to see green shoots will emerge from the tops of the bulbs.
  • Keep the roots submerged and change water weekly.
  • When the shoots are 8-10 cm long, you can plant them in the ground or a pot filled with good quality potting soil. You need to plant in soil as eventually they stop stop producing in water as the plant weakens from not having the right nutrients.
  • Snip off what you need, cutting the leaves all the way to the ground; the spring onions will continue to grow again from the cut end.
  • Spring onions can survive winter here in WA,. They’ll start perking up each year around springtime.
  • I recommend putting a few new starts into the ground to replace anything that looks like it is starting to struggle.

What’s the best fertiliser for spring onions?
Use a liquid plant food designed for herbs to promote healthy stalk growth.

I recommend Yates Thrive Vegie & Herb Liquid Plant Food every few weeks.

When to harvest spring onions in Australia:
Spring onions will be ready for harvest 8 – 12 weeks after planting depending on the conditions.

To harvest cut off your spring onions at ground level. Leaving the roots in the ground will mean they can re-sprout to give you a quick second harvest.

How to store spring onions:
Like most vegetables, spring onions are best eaten fresh. However if you have too many you can store spring onions in the refrigerator. Keep them in the crisper draw, sealed well in a plastic bag, and they’ll stay fresh for about two weeks.

Companion plants for spring onions:
Parsley and mint are great options to plant with spring onions. Capsicums, tomatoes, carrots and cabbage are also good options.

A couple of companion flowers for spring onions are roses and chrysanthemum.

Spring onions plant care and common problems:
It is important void over-watering, especially while they are germinating from seed as excess watering can cause the seeds to rot. Young seedlings are susceptible to snail and slug attack and need to be managed.

Check out our other how to grow in Perth guides:

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