[rich24uk]

Our local garden centre were handing them out for free so we took a few packs. Is it too late for them?

[mumofstig]

I doubt there is enough time for them to make bulbs, but you can plant them to pull as green onions in the autumn

[rich24uk]

Thanks!

[stainesbloke]

I hope it's not too late as I'm putting in a load this coming week.....everything is at least a month late due to the exceptionally cold and late Spring, so am keeping fingers crossed

[DD.]

From experience, MoS is correct. Expect no more than spring onions. I'd plant them close together to save space and grow something else.

[fatcat1955]

Onion's stop growing on the longest day when all the energy in the leaves is transfered down to swell the bulb. As you only have about 3 week's growing time i would say it is far too late.

[AnneB]

Onion's stop growing on the longest day when all the energy in the leaves is transfered down to swell the bulb. As you only have about 3 week's growing time i would say it is far too late.

I planted mine in early March but growth is very slow this year.  If they've only got 3 weeks more, there won't be much energy to transfer anywhere!   A shame, as onions from sets normally do well for me.

[rich24uk]

Am I right in thinking that they would not keep for next season? If so I will just bung them in and see what comes up

[DD.]

They will not keep.

[ConfusedGardener]

I also planted mine a bit late. I didn't realize they would stop growing in a few weeks!

How about artificially extending the growing season for them? If I bought a couple of those solar powered lights and stuck them in the onion beds so that it stayed light after the sun had gone down(effectively lengthening the day), could that work?

[DD.]

They have nowhere near the brightness required.

You would need Growlux lights, a mains power supply and a fat wallet!

[ConfusedGardener]

That's a shame. O well, looks like I'll have a fair supply of spring onions at least 

[olde9856]

Sorry but mid summer stopping growing is just not correct, they will keep going as long as the light and heat conditions are suitable

[Mark's Sussex Allotment]

Surely overwintering is the et to go then, if they stop growing mid June........

[simonwatson]

Sorry but mid summer stopping growing is just not correct, they will keep going as long as the light and heat conditions are suitable

According to what I've read, long day onions (typically what will be grown in Britain) will stop producing new leaves and start the bulbing up process once day length reaches 14-16 hours. Without this trigger for bulbing, you just end up with leaves and no bulb. The leaves will continue to grown bigger after this time.