As onions take a long time to mature (5-7 months), it is often better to buy them at the store and grow spring onions at home instead. Different regions have different sowing times as well and this needs to be taken into consideration when choosing your seed variety. It is best to speak with a garden expert in your area for help with sowing times and seed choice.
How to grow onions – planting
Onions (early varieties) can be started in seed trays in the following seasons: Warm areas = sow late summer to late autumn.
Temperate areas = autumn
Cool areas (short days) = sow from autumn through to spring
As with all home vegetable gardens, start with lots of compost and other well rotted organic material to prepare your bed. If you are sowing direct to the bed, then make a shallow drill to sow them about 1cm deep, cover with compost and water lightly.
After 10 – 14 days your seedlings will begin to emerge. Thin them out to 2 – 3 cm apart. Later on thin again to 7 – 10cm apart choosing the weakest seedlings to discard.
Long term care
After your second thinning all you need to do is weed by hand around the plants. They should not need more feeding, just an abundance of water in their initial growing season.
Onions can take 30 weeks before being ready to harvest. Bulbs are not ready to pull until the tops start to die off and fall over. After lifting the onion bulbs, leave them in in partial shade for a few days to dry out.
When to plant: Plant out young plants according to variety and season.
How many plants: Dependant on your needs. Over plant at first as you will thin out.
How long to harvest: When foliage has died off.
Successive planting: If your region allows for it plant every two weeks.
Next time you are making a roast, put in a tray of onions. Simply peel the dry skins off, quarter and lay out in an oven dish. Drizzle with olive oil and roast with your main meal. Even more delicious is adding a few whole cloves of garlic.