Onions from a big family
There’s nothing to cry about when growing onions, writes Colleen Simpson.
The allium genus is a large one, so even if you don’t have room to grow traditional brown onions, everyone has space for a clump of spring onions or chives.
Traditional onions (Allium cepa) aren’t difficult to grow, but they do take up a fair amount of space in the vege garden and for a very long time. They are usually cheap to buy too so it’s not always economic to grow your own. However, chives and spring onions take up very little room, are more expensive to buy and don’t store well, so it’s definitely worth growing a patch.
When to sow
Regular onions are sensitive souls – day length-sensitive that is. Short-day varieties start forming a bulb when day length is between 12-14 hours whereas long-day onions supposedly do this when day length is between 14-16 hours. For this reason short-day varieties suit northern gardens, while long-day types prefer languid southern summers. Why does this matter? Well, if you sow a long-day variety in the far north, it’s likely to bolt to seed before it develops decent bulbs. Start growing onions any time between July and September. Chives and spring onions can be pretty much sown year-round. Leeks can be grown into early summer but the longer days mean they are more likely to bolt to seed.
Growing instructions
Onions, chives, spring onions and leeks are all pretty similar when it comes to their sowing requirements. Sow the small, flaky, black seeds shallowly or directly onto the surface of seed trays or prepared garden soil. Once they are ready to transplant, the seedlings need different treatment.
Onions need the longest growing season – usually well over six months. Plant them into free-draining weedfree ground when they have four to six true leaves (at around four months). Plant them no more than 2-3cm deep to avoid them being long and misshapen.
When it comes to onions, goldenfleshed ‘Pukekohe Longkeeper’ is a long-standing Kiwi favourite because of its resiliency and good storing qualities or choose colourful heritage varieties which are available as seed from Kings Seeds or Egmont Seeds.
Spring onions should be planted in dense clumps or close together in rows to encourage narrow stems and tall straight stalks. Plant deep enough for the white part of the stem to be