Would pelleted chicken manure before planting help? Or home-made compost? Anything else?
At planting out time I would only use a slow release general fertiliser such as FB&B or Growmore to let the plants take up what they need over the winter which you will find is not very much as they will go into a semi-dormant state when the temperatures drop!
In Spring as the soil is warming up then boost them into growth with your pellets, or some such high nitrogen fertiliser.
If you do it the other way around you could promote too much lush growth going into winter which may get killed off with the frosts then your plants would have to start again.
It might not be as the experts would suggest but that the way I do it and it works for me.
I find the type of winter we get seems to play a part in cropping i.e. I like it to be really cold and not cold and wet as we had last winter, which in my opinion I think caused the poor cropping.
This year I have bought some new stock from Robinson s (usually I save my best bulbs for planting out) So I am hoping for a cold frosty winter.
Another factor I see with a cool wet winter is that the wildlife seem to be well off in feeding terms as there is plenty around for them to feed on, so they do not seem to forage for the weed seeds and pests on the soil as they would in colder weather.
I think last winter is one of the reasons for me having a bumper crop of chickweed and Fat Hen the birds did not eat the seeds!
As I say....these are only opinions!..Tg