[wbmkk]

last year was my first with an allotment, so I planted quite a few onion sets ... some directly in the ground and others in small 3" pots in the greenhouse, to give them a head start.

Although I was delighted with the crop ... quite a few (maybe 10-15%) of the plants went to seed early.

I now know I should have opted for heat treated sets, rather than the untreated ones in the local store.

Which varieties are good, for non bolting as well as storage.

thanks !

[Fisherman]

Over the years I have tried various onion sets, standard and heat treated and have always had 10%+ going to seed. I now only grow onions from seed, they are cheaper, keep longer and not as many go to seed although they are a bit of a faff to sow them in pots to start them off in the greenhouse or cloche. I reckon I have enough left from last years crop to keep me going well into March. This reminds me I need to sow my onion seed ASAP after this next cold snap but no rush.

[wbmkk]

I now only grow onions from seed, they are cheaper, keep longer and not as many go to seed

last year I actually bought onion seeds ... I thought sets were cheating

The seedlings were in a propagator (heated) but all of a sudden they all started falling over (I think it's called damping off) The sets were therefore my 2nd attempt at onions

By the way .. I always thought Christmas Day was the onion sowing date, or is that just for 'show onions'

[sunshineband]

Show onions do need a longer growing period wbmkk, and some are even sown before midwinter 

I have some seedlings (still at one leaf stage) and will be planting both heat treated and normal sets too, as I am keen to see what difference it makes to bolting. They are not all the same variety so it will not be a 100% fair test, but it'll give me an idea I hope

[Salmo]

Heat treated sets in my experience certainly give less bolters. There is no hurry to plant sets, treated or not, and starting them off in pots is not needed as they grow away quickly when you plant them. Wait until the soil warms up. Red varieties bolt more than red.

I usually sow onion seed in February, sowing up to about the end of March is OK, in fact sowing them directly in the soil is OK. The later you sow the smaller the onions. Cooks usually prefer smaller anyway.

[mumofstig]

Cooks usually prefer smaller anyway.

I don't know about that. I prefer larger onions 

[sunshineband]

Cooks usually prefer smaller anyway.

I don't know about that. I prefer larger onions 

I like the bigguns too 

[wbmkk]

Red varieties bolt more than red.

?? 

Which colour bolts the least please

[snowdrops]

Red varieties bolt more than red.

?? 

Which colour bolts the least please

White

[DD.]

Cooks usually prefer smaller anyway.

I don't know about that. I prefer larger onions 

That goes for this household as well! Less faff in the prepping.

[Dave NE]

Any of my onions that bolt this year will be frozen and then used in an onion recipe which was on recently on the Jamie and Jimmy show, it went down a storm in their café, Dave

[Lisbon67]

Unless you're very short of space, heat treated sets are a waste of money in my opinion. I've only ever grown cheap, untreated sets from poundland or wilkos. Although around 10% have bolted, overall results have been great and I've ended up with far more top notch onions post pound for pound. Even the bolted ones keep for a month or so so plenty of time to get rid of them first.