Forum home Fruit & veg

Onion Harvest

Every year (Last three years) I have had what I think to be as a novice a good harvest of onions but I'm struggling to store them for long before they start rotting.

I carefully dig them up with a fork gently teasing them up and out before laying them out on the soil for a week or more before hanging them up in my garage.

However I struggle and I think one of my problems is that my garden is a damp garden at harvest time and on sunny days it is very humid in the garden.  My garage is south facing and gets warm.

This year my onions are huge and looking very healthy indeed at the moment.   There not ready for harvesting yet and I'm wanting to do better this year at preparing them for storage and getting them to store longer.   I reckon I waste roughly half of them as they go rotten in storage.   This year due to recent prolonged rain my garden is saturated at the moment (a lot more than normal).   I suffer with a very wet garden in winter.   As the sun comes out over the next few days / weeks yet again my garden will be extremely humid and damp, not a good environment for harvesting onions, or so I believe.

What am I doing wrong?

How can I harvest and store them better for longer and reduce wastage?

Has anybody tried using a dehumidifier to dry out there onions prior to long term storage in a garage?

Any, all ideas and suggestions welcome.


  • SkandiSkandi Posts: 1,618

    Ok well I live in Northern denmark, so it is very cool and damp at harvest time (September for me) last two years I have grown red baron (red onion) bedfordshire champion and a generic yellow onion from here. They have survived until June where the last decided to sprout.

    I wait untill all the leaves have flipped over then I pull them out and put them strait into my barn where they sit on the floor (concrete) layed out in single rows untill they are entirely dry and crispy, this can take nearly a month.

    Then I sort them, any that have split into multiples or have any damage get taken into the kitchen for quick use the rest continue to the next stage.

    I then string them up into cheats plaits (using string in the middle) and hang them in a dryer barn room, where the temperature varies from around 5 to 0 all winter I also keep my carrots parsnips, potatos etc.

    I don't get any that rot, but some start to sprout from around March, I found that the red onions last longer than the whites, but the whites last reliably untill April.

  • SkandiSkandi Posts: 1,618

    It won't let me edit so..

    PS. I also live in a bog with the watertable less than a foot under my garden, so I don't think that wet soil is a problem!

  • I have thought about removing them from the garden altogether and storing them initially on my flat garage roof for a few weeks.  My winter water table is roughly 18" below soil level.

    I think you're right about the wet itself not being a problem directly but I think it could be the high humidity brought about by having wet soil at harvest time maybe.  My garden is in the bottom of a bowl and is surrounded by firstly high walls and hedges then above that my neighbours houses all around are higher than mine.   The following two images give a sense of just how humid my garden can be.  These were taken after several weeks of dry weather in the spring.   You can see the sunlight shinning through the moisture.



    Last edited: 25 July 2017 13:14:01

  • WelshonionWelshonion Posts: 3,114

    The only thing I can suggest is that you are harvesting them too early.  I usually wait until the roots have let go and the foliage has not just flipped over but dried off completely.  I ensure once they are out of the ground that they are not rained on.  I usually ripen them in the greenhouse and store them in plastic trays, but that is just a preference of mine.

    The length of time an onion will store is also dependent on the variety.  Remember farmers who grow for supermarkets have access to all sorts of growth retardants which they use to make sure the crop lasts well into next year.

  • Thank you again for your replies.

    Just harvested my Shallots and Garlic today, excellent crop this year and no fungus or premature rot to be found.   I did have fungal growth on my Garlic at harvest last year but the garlic and the shallots have so far always stored well and well into the following spring.

    It's only the Onions I seem to have a problem with, at harvest I often find some have already got fungal growth on there undersides.   Unfortunately I don't have the luxury of a Greenhouse or Barn or some other ventilated building or structure to dry them out in or under at the moment.

    Decided that this year i'll store them outside on top of upturned plastic grates on the garage roof in full sun for a good few weeks before I bring them indoors and store them in the garage.

    I have to try something different this year or stop growing onions.

    Thank you again.

  • BobTheGardenerBobTheGardener Posts: 11,391

    Perhaps your garage just gets too warm for good storage?  Like most fruit and veg, onions need to be stored cool once hrvested and dried.

    A trowel in the hand is worth a thousand lost under a bush.
  • Just thought i would follow up on what happened with my Onions this season so far.

    Well i did well this year, a good if not my best harvest.  I decided to firstly lift them and then wash them straight away removing all soli etc completely.  I then placed them gently up onto a large flat roof facing southward for a couple of weeks, then I placed then into a shaded glass house at a friend’s house for another month before platting them together and hanging them up in a garage.

    For the first time I’ve had no neck end rot or indeed any other infections etc and I’m now concerned that I might not get them all eaten before next year’s crop!

    I have had a few shallots go mouldy this winter but very few though.

    Not sure whether washing them has done the trick or not but in previous years my losses in storage have been high, this year none at all so far.

  • ColinAColinA Posts: 367

    This year I had an excellent crop of onions, last year I had a crop failure as they just stopped growing about the size of a golf ball.

    I lift mine when the leaves start falling over, then clean off all soil and lay them on a bench in the shed till completely dry, I then cut off the tops and store in plastic trays in the loft,

  • WelshonionWelshonion Posts: 3,114

    Never washed an onion, in my life. I leave the soil until it is dry and I can remove it manually.  IMO washing would encourage rot rather than prevent it.  But, if it works for you.....

  • Not washed in previous years but leaving them with soil on them and then gently removing it later by simply and gently rubbing it off with the my hands i've lost 80%+ of my onions in storage before Xmas every year to rot and fungus growth.   In addition the garden has a wet humid enviroment, you can feel the humidity in the air when gardening.

    It could just be raising them much higher off the ground / soil onto a flat roof into a much dryer exposed place that has improved things or the washing or both i don't know but I had to try something different or stop growing onions and so far what a huge difference.  It may be just a fluke it may be something else i'm unaware of but i have to try something or stop growing onions.

    It's worked, or something different has worked this year' i'll try the same next year and see what happens.

Sign In or Register to comment.