[princesslayer]

My red onions are bolting. Are they ruined? Is it lack of water? I pulled one up and it is very slim so not really worth eating. White ones seem ok so far. Shall I leave them and see what happens?

[doganjo]

I've taken the tops out of mine and they've improved.

[Carse Goodlifers]

Any crop which bolts is as a result of a stress factor e.g. lack of water, sharp drop in temperature or vastly fluctuating temperatures from day to night.
Red onions are notorious for bolting - I've stopped growing them for that reason.
As doganjo says, take out the growing shoot and it should be ok.

[Millwood]

Or use them as spring onions, that's what we're doing with our bolted lot!

[princesslayer]

Thanks all, do you mean take out the flower shoot?

[doganjo]

Yes.

[cloddopper]

When did you put your red onion sets in ?

 Onions like most plants respond to the lengthening daylight hours& heat  . flowering.
Couple this with a fair amount of water /rain and a  very fertile recently manured ground then the conditions for bolting are ideal .

I over wintered my reds on ground that was fed with composted manure 18 months ago , so far out of 50 sets only seven have broken to flower but a lot of the onions are skinny with too much tops on them .

 The conclusion I come to is .... Too much water & too much food ,as they are in full sun all day . I can control, the water and food angle ..this autumn I'll try again without adding the compost again nor will I be giving them a feed of fish blood & bone as a top ... side dressing.

I'll also try a late spring planting for some of the red sets rather than putting them in theb onion beds at the same time as the Sturton giants  so that they have half a chance of getting less rain during the summer as well
 

[pgkevet]

Some of my reds have bolted this last week.. certainly not too much water for them but the ground is very well manured - a good layer of woodchip and later of rotted horse 2 years ago and last year a triple dressing of cow slurry all ploughed in.

[princesslayer]

Mine are likely to have bolted from too little water. The bed had compost this year but not animal manure. They went in quite early (early April?) and shot away, lots of tops, others I have aren't growing so fast so probably soil is a bit rich.

[cloddopper]

I've just remembered .. most white onion sets are heat treated so that the flowering growth node is held back . These are often called Japanese onions or heat treated onions.

I guess/ hope  it won't be long before we get GM red onions that have this valuable trait in them.
 

[Rosiecrad]

This year I've followed Charles Dowdings advice and planted my red onion sets in April ( late April I think) and so far they have not bolted, I have something like 100 red sets. It's been very very dry here in Somerset so so far seems to be working.

[Carse Goodlifers]

This year I've followed Charles Dowdings advice and planted my red onion sets in April ( late April I think) and so far they have not bolted...

Being up in Scotland, when we had the allotment, we had no real option BUT to plant in April due to the weather and the temperatures some years...........still made no difference to us