[A Reyt Tayty]

Do onions all need to be harvested and stored together, or can they be left in the ground until needed?

[DD.]

They need to be dried, dried again, then some more.

Once you've done that, repeat the process and store.

Do NOT leave in the ground.

[LilacSandy]

I agree with DD that they should not be left in the ground to overwinter, however I lift mine as and when the leaves tell me to, i.e. bend over and go yellow. 

I harvest the autumn sown sets first and then the spring sown sets but my onions from seed are still growing and the leaves are green and upright so  I will be leaving them for a couple of weeks to swell.

[Auntiemogs]

Also a good idea to check the storage properties of the onions you have i.e. my Autumn planted sets (Senshyu Yellow) are not known a long keepers (and they were right) so I chopped a load and froze them. 

[A Reyt Tayty]

Thankyou chaps.
What is the latest you would leave them in before harvesting?

[LilacSandy]

I would not leave mine in the ground later than the end of the month, however if your leaves are bending or going yellow get them out now.  As DD said they need a lot of time to dry so you need to get them out before the really bad weather starts.

If I were you I would pull one or two and have a look to see how they are doing.

[shokkyy]

I can't decide whether to lift mine or not. The leaves on most are still green and strong looking, but most of the bulbs have lifted up and grown the brown outer skin - am I likely to still get more growth from them after they've done that?

[DD.]

Simply wait until the leaves flop over. Onions will tell you when they're ready.

[devonbarmygardener]

I lift onions when the leaves fall over and start to go brown.
Then I leave them to dry in the shed on a table.
Then while the leaves still exist and are all brown and crinkly, I then tie or plait them together using the leaves and hang them up in a cool pantry.
I find it's the only way they don't rot.
I stored them in a veg trolley last year and had a utility full of tiny flies as a couple of them rotted.

[The Golden Heap]

 I kinda lifted mine a little and bended them over as advised by my allotment neighbour, all dried good , now in shed and taste devine!  Although shed has been a little hot of late

[sunshineband]

I kinda lifted mine a little and bended them over as advised by my allotment neighbour, all dried good , now in shed and taste devine!  Although shed has been a little hot of late

Hope they don't cook then  :blink:

[The Golden Heap]

Been hot today no in shade and not cooked!!  i hope

[DD.]

I kinda lifted mine a little and bended them over as advised by my allotment neighbour, all dried good , now in shed and taste devine!  Although shed has been a little hot of late

The RHS not longer recommend that practice.

Although it is sometimes suggested to bend over the foliage or gently lift the bulbs to break the roots this is no longer recommended.

Full link here:

http://www.rhs.org.uk/Gardening/Grow-Your-Own/Veg-A-to-Z/Onions---shallots

[aligemini]

I waited until our Shallots and Jap Onions went yellow/brown then lifted them all and laid them out to dry in the shaded part of the G/H - Garlic too. - That was back in the tale end of July. Yesterday I topped and tailed them then hung them up in the garage in my Daughters old teedy bear hammock I doubt I will need to check them over as we will be pickling most of them very soon however if we'd got enough to store I would check them periodically for rot.

Ali.