Onion sets Bolted

'Only' 20 - 25% of my overwintering onions bolted (none were red ones). None of my early seed sown onions have bolted and the bulbs from the seed sown ones will be much, much larger than from setts. I'll still put in more setts this autumn though - never put all my eggs in one basket + they come much earlier.

 

Most of my onions have bolted as well they were autumn sets could this be to that early hot and dry spell we had

 

These sets were planted in (I think) mid march and have nearly all bolted so I've cut the flower stems off and will see if the grow any larger.

 

They look alright to me.

 

This thread has raised yet a few more questions for my onion growing attempt. Luckily non have bolted , I am growing Sturon and red onions from sets in containers planted Mid March to end of April. Now the questions..........
Aren't onion sets grown from seeds,if so what is the advantage of growing from seed ?
Onion sets can be heat treated to prevent bolting ,although on the bags I bought (Wilkos ) it did not say that they had been treated. Is it possible to heat treat onion sets yourself with a blast in the microwave ?

 

Slightly different, but for the first time I'm having a go with some shallots sets, the growing of which I know absolutely nothing about (except what I read in a very old gardening book that once belonged to my Grandad). The conditions I could provide seemed to correspond with what the book said, - 'plant on the shortest day; harvest on the longest' (or thereabouts) - so in they went. Eventually, they sent up some 'growth' and ...... well, that's it really - there they sit, their green leaves blowing in the wind, of 'small clumps of bulbs joined at the base' there is no sign!

I wonder, is this nature's way of telling my I'm not a natural grower of onions?

 

Hiya F/M.

I'd be interested to know, did you plant them direct or start them off under cover? Seems to me that if they were planted direct, it's a long time sat there waiting for warmer conditions to encourage growth. If started under cover, I would imagine that from such an early planting, they would soon want to 'stretch' their legs and one would be faced with the prospect of planting out in less than favourable conditions.

I know that for the biggest onions, seed are sown on the longest day(traditionally), but Shallots? I seem to recall my Dad used to start off his Shallots in the greenhouse, but I think it was later, around February. I'm certainly no expert, so it would be nice if someone could add more
BTW, I normally plant my Shallots direct, in March.

Cheers...Freddy

 

I found this extract below on the Marshalls site on heat treating onion sets , its 30°c for 20 weeks !!!! So I can forget that .
"Our Heat Treated Onion Sets are specially heat-treated for 20 weeks to help prevent bolting. Heat Preparation also extends the growth period which means that greater yields can be achieved."
When I do buy a bag of onion sets I only use less than half in a few containers I have . Would they keep for 12 months to the next season in a cool dark garage , or could I plant them close together with my spring onions and pick them as small salad onions Will they (sturon ) be edible at this size ?

 

I think onion are a great crop to grow as you can actually pull them whenever you want during the growing season, go a bit soft if left in over winter.

Its just that most of us are actually looking for something to store over the winter period.
Not sure your sets would keep till next year Harry. I'd just plant them close together, they do actually just push one another away and get to a reasonable size.
I grow my seed grown ones that way.

 

Good point that Pete

Once mine get to a decent size, and if I need some, I don't hesitate to pull some up

Cheers...Freddy

 

Found this thread very interesting as many of my onions (and beetroot) have bolted. Seems from what the experienced gardeners say that using seed is less likely to result in bolting so that will be my tack next year. By the way, I have just had half a ton of well rotted horse manure delivered as I did last year but hope the horses have had a different diet as -this year- my allotment was festooned with chick weed and nettles. Any hints as to how to limit the number of the said weeds other than pulling them out as soon as they appear? A Corn.

 

Probably only three choices. One you have already mentioned, pulling up the weeds. Second, you could use a weedkiller, something that contains Glyphosate works best for me, but you would need to apply this before you plant the onions, obviously Thirdly, you could lay over the ground a layer of black polythene, and plant though that, by cutting slits to plant through. Others may be able to give other options

Cheers...Freddy

 

It's very strange at times this gardening/growing lark.

Last year at our allotments plot holders had wonderful Onions, whereas mine where small and pitiful, and most bolted too.

This year it's the complete reverse, many plot holders tell me how rubbish their onions are and how they have bolted, whilst mine are growing very well and I have had only one bolt!

Work that one out if you can.

Steve...