When to plant winter veg seedlings?

On 11th September I went along to the local nursery to buy seedlings for the winter vegetable patch. As is so often the case, there was a man standing chatting to the proprietor and hogging his attention but not buying anything nor letting anyone else get served.
I selected some trays of seedlings - Florence fennel, spring cauliflower, savoy cabbage, leeks, cavolo nero and red cabbage (just a few of each) - and brought them to the counter. The man started to talk to me too and when I had paid and was loading up the car he followed me out and said 'You're far too late, you know. These should have been planted 10 days ago. In fact 20 days ago would have been better. Really it is an August task.' A bit taken aback, I replied that I couldn't imagine how little plants could survive in 40 degrees heat - in fact even today was uncomfortably hot in the high 20's. 'Of course they need to be watered' replied Signor Noioso, undeterred, 'and that way you get fennel as big as a football'.
Arriving back home I ran into the next door neighbour who confirmed that yes he too had already planted all his veg seedlings ages ago, although he was about to put in some winter lettuce plants. Strange because I planted at about this time last year with no complaints from anyone and reasonable results.
So I consulted my calendar for planting in accordance with the phases of the moon. Maybe this is more like it. The tradition is to plant seedlings during a waxing (growing) moon and sow seeds during a waning (shrinking) moon. The new moon (i.e. no moon at all) was today. This means that for the previous 14 days the moon had been waning - no good for planting. But now it is about to wax again so perhaps I will be alright? Who knows.
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