Funnily enough, I was speaking to a commercial supplier of onion sets last week, about autumn-planted sets, as I've always been of the, 'Bung in early, get bigger'uns,' approach to gardening.
She said that no farmers/producers would even begin to plant out the sets until the first week of October [gnomey squint at calendar: ooh! Tomorrow!!].
I bought two bags and planted some out last year in an unusual frenzy of activity, as soon as I got 'em, and using - in addition to garden implements - what I considered would pass as logic: the sooner planted, the larger, bigger, better onions I would get. Sooo, in they went in early September.
I then found the misplaced other bag of the same variety, same brand. These got planted in my next frenzy of activity in early NOVEMBER. I planted them with a sinking heart, and a head full of curses for tardiness, procrasination, money down drain, etc.
By spring, the September-planted ones were slightly ahead of the other batch. Then
The September-planted ones were rubbish: they didn't bulk up. Then they got white fungal rot.
The November-planted ones were the best onions I have ever grown. They were enormous, healthy and, if an onion can be described as such, vibrant. Almost architectural, they were. People came from other plots to gawp at them, even.
Both lots were grown within inches of each other, adjacent blocks on my lotty: one lot went on in the half-row where the first bag had run out.
I'm going to plant some successionally this year, Just To See What Happens.
Mind you, I've managed to order a SACK to sell on to us at the allotment to save loads: they are about 20% of the price of garden centre-bought ones. The commercial grower is doing me a favour, as she usually fufils orders that would cover a small African nation knee-deep in sets, I discovered.
Gnome: I'd like to buy some sets, please.
Her with the Sets: How many would you like?
G: Oh, I was thinking, er, um, one or two?
HwtS: Yes, that would be fine. What size lorry load would you like to order?
HwtS: Hallo, anyone there??
G: [squeaky high voice, faintly] Do you do, um, BAGS??
HwtS: Yes, but they're only 25 Kgs.
And so on.
Anyway, I mentioned my marvellous differences in results to The Lady, and that's when she came out with the gem of info at the start of this overlong post.