AFTER passing through the shortest day in the year, we've arrived into the main onion sowing and planting time.
It is really all about how our fluctuating day length - that is hours of sunlight - determine the way most long-keeping onion plants develop and grow.
Popular long-keepers include common brown onions and the New Zealand-bred cream gold.
These valuable vegetables are highly sensitive to the slightest changes in light. To grow properly they need constantly lengthening daylight hours, such as we are now getting until just before Christmas.
First of all, be warned about some of the bundles or punnets of onion seedlings that are now on sale.
Many extra-large seedlings of long-keeping onions could be a waste of time and garden space.
If raised from seed sown last autumn - as some undoubtedly are - it is far too early to get them started.
It's true, if we plant these big, lanky onion seedlings out now they will grow with impressive vigour. But keep in mind they have already been growing through the year's most significant day-length period.
We've just had a reversal from continuously shortening hours of daylight to gradually lengthening ones.
Let's be honest, we hardly notice this change at first, but early-started onion plants respond almost immediately.
They are biennials - grow plants and bulbs one year and go to seed the next.
This light length change makes the big onion plants "think" they have been growing for more than a year.
Consequently next November, many of these apparently healthy-looking onions suddenly start forming thick necks and then bolt uselessly to seed.
That's the end of a crop.
So months of time and garden space have been wasted and by November it is too late to plant replacements.
Either sow seed directly into a garden bed now, or buy punnets of those tiny, recently germinated seedlings.
They are identified because they are small, grass-like and have little black caps stuck on the tips of each leaf.
Capped seedlings may appear insignificant but are the best young seedlings to buy, because they are too young to be tricked by day-length change.
Onion seeds are black, angular and tough enough to germinate at low temperatures. If the soil is extra cold and wet, sow seeds into trays or punnets filled with good quality seedling-raising mix.
It helps if a good handful of dolomite limestone is added to each half-bucket of the stuff and mixed well in before filling containers.
Then sow the seeds evenly - but sparsely - over the surface, cover with a fine layer of dolomite and water in.
Leave in full sun and keep just moist.
Healthy seedlings will up like grass in a couple of weeks and can be safely planted out in the garden during August or September.
Sowing onion seed into open ground is easy. Onions for long keeping don't need extra-rich soil.
It makes them grow too big and soft so they will not store for long after harvesting. They also taste weak.
Use a bed manured for another vegetable last summer.
I follow tomato plants with onions without using fertilisers, apart from a double handful of dolomite limestone, to each square metre and then rake it in.
A fistful of sulphate of potash to each square metre also helps to form strongly flavoured, longer-lasting onions.
While raking and cross raking the surface, walking over it while just moist provides the firm conditions onion plants love. The coarse black seed mixes easily with sand to enable easier sowing.
Sow seed in rows, circles or little clusters. Even clusters of space-saving onion plants thrive because as they grow and swell, they push each other aside without competition.
Planting small seedlings is dead easy.
Make shallow straight grooves in the soil using the tip of a garden stake.
Carefully remove all seedlings from containers and shake off all soil.
Gently disentangle the plants, then move along each bed, draping each seedling quite flat on the ground, leaving only the roots to dangle in the groove.
Cover just the roots with soil.
The plants look silly lying flat, but after a week all will be standing straight up.
Shallow planting allows the bulbs to properly swell, while almost sitting on the surface so the sun can ripen them.
This need for sunlight on the maturing bulbs is why onions should never be mulched - it also sends them mouldy.
