Having grown onions successfully year after year with good yields, I soon realised I should learn how to store onions properly in order for them to keep for as long as possible. I learnt the hard way that there’s little point putting effort into sowing seeds or planting sets, running around your veg patch like a demented scarecrow, arms-a-flapping while you try desperately to protect your tiny onions from birds and cats that seem determined to dig them up, just to end up throwing out rotting onions by the bucket load come late autumn/early winter.
If like me you grow a lot of onions, then storing is vital to see you through winter and beyond. Below is what I’ve learnt so far, it has helped to keep us in onions for some time but I did make the mistake last year of unwillingly feeding a hungry population of field mice in our garage (a hazard of living so near to farmland and woodland), so a more suitable place has to be found for the trays this year.
Lift onions on a dry day, lay them out on top of the soil for as long as possible if weather permits with bulbs fully exposed to the sun, otherwise put them straight onto racks or greenhouse staging in an unheated greenhouse, conservatory or shed. Leave them for as long as possible to fully dry, the leaves will all but wither away but that’s fine. Once the outer layer of white/yellow skin onions starts to darken to a caramel colour (red onions will darken) and become crispy to the touch, drying is well underway and your onions should store well. Drying is key to storing onions for as long as possible.
Discard any bulbs that have signs of fungal growth or disease (avoid compost heap) and use spongy or sprouting bulbs immediately – they won’t store. Once the bulbs have fully dried store them in nets, trays or tie them in bunches and put in a cool, frost-free place such as a shed or garage. If your unheated greenhouse is guaranteed to be frost-free then this would be suitable also. Red onions tend not to store as well as white/yellow onions, different varieties may vary with storing abilities too so it’s best to check this before purchasing onion sets/seeds.
As I said before, this procedure works for me (apart from mice chomping their way through a lot of my onions in the garage) so hopefully this will work for you also. If you have any other points to add with regards to storing onions successfully please feel free to drop them in the comments box.