How To Grow Onions
Part of our heritage week focus on creating a traditional Irish kitchen garden
How to grow and harvest Onions
Onions are an extremely popular crop as they are so versatile and easy to grow. Whilst they can be grown from seed it is easier and usually more fruitful to grow from sets. Sets are under developed bulbs that you plant straight into the soil.
Onion sets are planted around mid to late March although you can of course plant them earlier if using a polytunnel / cloche (a cut 5 litre water bottle makes a good cloche) and should be spaced around 10cm apart in rows spaced 30cm apart.
When choosing your bulbs from the set packet make sure to go for the healthiest looking ones and discard any that look too thin/weak/brown spots.
To plant your onion sets simply dig a small hole for each set placing the onion neck upwards - in fact to avoid weeding you could cover your prepared soil in black material (hipex) and then cut the hole for the onion to be placed into.
Cover the onion so that just the the tip of the neck shows slightly above the surface. It's a good idea to cover your planted sets with anti-bird mesh as birds do love to pull them from the ground undoing all your hard work.
Onions can get dry very quickly if the weather is hot but make sure to give them a really good watering every so often rather than small amounts all the time.
When the stems of your onions have turned yellow and fallen over you know that they are almost ready for harvest - about a week later. Carefully lift them from the soil preferably on a sunny day,leaving them to dry out for a few days (weather permitting) on top of the soil with excess dirt removed. If the weather is bad move them to a dry place like a shed or porch and lay them out flat on newspaper to dry taking care not to bruise them.
When drying is complete you can then remove the tops cutting about 2cm above the onion itself using a sharp knife. If you wish to store them you can do so by hanging them in mesh bags or using string, in a cool dry shed for about 3-4 weeks. A good storage onion kept in a cold, dark place will last 10 to 12 months.