How To Grow Great Onions From Sets

I get asked this one a lot... How does one grow really great onions that size up well and taste great?

Here comes the how-to for a really successful onion growing year... 

Start with great soil!

The secret to great onions is to have really great soil to grow them in...isn't it always? Great soil is always the answer : )

You want to start with rich and fertile, well-draining soil that is loose, friable and weed-free. The onions want lovely loose soil to a depth of at least 6 inches.

Amend your bed with manure or compost. If you feel your soil needs a boost, add some bonemeal and sulphate of potash for great onions (yes, these are organic amendments). 

Do not go heavy on nitrogen fertiliser though (blood meal, alfalfa....) as it will give you all tops and small bulbs.

Ensure that you have great drainage as onions will rot if grown in wet beds. Raised beds work really well for onions, but if you do not have them and tend to have heavy soil, you can simply make a raised hump for your onions to grow in. Make this hump about 6 to 8 inches wide and 3 to 4 inches high. Plant along the centre of this hump.

Growing onions from sets  

Sets are small onions that were grown the season before and then put into dormancy. They are super easy to plant and grow. 

 

Can be planted in the garden 4 to 6 weeks before last frost (mid to late March here in the Nanaimo area) if your ground is dry and ready to go. Do not plant in wet, soggy soil. They will grow just fine and size up just fine if you do not get them planted till mid, or even late, April.

I tend to plant mine up in the month of April or May but have planted them as late as early June, as well. They always do fine either way!  

 

Discard any onion set that is mouldy or shrivelled up.

Soak the onions in a bit of compost tea, or warm water with a bit of liquid seaweed or kelp in it. This will help re-hydrate them, get them to break dormancy and start growing faster.

Soak for up to 24 hours. You can soak them anywhere from an hour or two while you prep your bed to overnight. Just pop them in to soak the evening before you plan to plant them up. 

Drain and plant. Use the seaweed water/compost tea to water them in after planting.  

 

Push into your loose and friable earth with the root end down, pointy end up. Place about one inch deep, just deep enough that the tip of the set is showing. Plant 4  to 6 inches apart, in rows that are 12 inches or more apart.

 

Water in well, to a depth of 4 inches to help them root in well. Water every couple of days to help them get well rooted in and growing. 

How to grow and care for your onions

 

Water once or twice  week to to a depth of one inch. Do not over water or your onions will rot. 

 

If you have been feeding your soil the no-dig, organic way, you should not need to feed the onions during the growth period. You will get soft onions if you feed them

If you really feel that they are lacking and need a feed during the early stages of growth, spray with liquid seaweed or fish fertiliser as a foliar feed every two weeks in June and maybe once in July. Then stop.

How and When to Harvest

You can harvest immature onions at any time during the growing phase for your cooking or kitchen needs.

If the soil is too high around your bulbs as they start to size up, brush away the soil so that just the bottom part of the bulb is in the soil. They should look like they do in the picture above. 

As the tops begin to fold over at the neck, they are nearing harvest time. Do not water at this time, let them sit dry until most all of the necks have bent over. 

You know that they are ready once the tops begin to yellow and fold over. When most of the onion tops have folded over (80% or more), give the others a hand by pushing them down yourself. Leave in the ground for another week to 10 days to finish maturing.

If you leave them in the garden for too long after the tops flop over, they will begin to rot and die as they are no longer growing, their job is done, they are maxed out.

On a sunny day, pull the onions gently from the ground. They can be left on top of the garden bed for a day or two to start the curing process. Do not wash or spray down with water!

How to cure your onions

Onions can now be braided and hung to dry in a shaded area, somewhere with good air flow and no direct sunlight... carport, open sided shed....

They can be also be laid out on tables to dry. This is how I dry mine ... place them in a dry, shaded area with great air flow. (Under the carport is a great place for this!)

You can also simply lay cardboard or newpaper on the carport floor and spread the onions on top to cure.

To Store/Keep your onions

Leave to dry completely for three weeks. If they are not completely dry, they will rot in storage. When dry, they will feel lighter and the skins will be papery and dry.

Clean up the onions by removing the roots and the tops. 

Place into mesh bags or crates or baskets (I use baskets) and store in a well ventilated area.

Note #1 - Any onions with bull necks (thick, fat necks) will not dry and thus are not suitable for storage. Take these ones into the kitchen with you, clean them up and use them up first. They will store in your fridge for a week or two. Can also be chopped and thrown into the freezer for soups or stews.

Note #2 -  Not all onions are long keepers/good storage onions. Sweet onions like Walla Walla will not keep for long so are good ones to harvest throughout the season instead. 

For good keeping onions, you want the zesty reds and yellows, like Stuttgarter. 

Happy Onion Growing!