Peter – I”m only intending setting out 15 sweetcorn but as I’m using a new seed source I germinated twice as many to be sure I got 15 good ones. Now I know how good they are, I”ll sow fewer in future – 20 – 24 probably.
As for fleece, my experience this spring (my first time doing it a lot) are as follows:
1. Parsnips germinate beautifully under fleece after sowing prior to the March full moon. Boltardy beetroot germinated very well under fleece after a sowing in the first week of April.
2. Transplanted lettuces and spinach really benefit greatly from being under fleece. Open to the elements, they really don’t grow very much at all, but under the fleece, they both do really, really well. I am expecting to harvest my earliest lettuces around May 15th, way earlier than I’ve done before and this is a much cooler later spring. This justifies the experiment of transplanting lettuce as an early crop prior to sowing runner beans in mid-to-late May.
3. Transplanted peas grow on terrifically under fleece (whether they really need it I don’t know, but I transplanted some Zeebrune shallots in front of them and they definitely need it).
4. Carrot germination has been relatively poor, but it may be the source of seeds rather than anything to do with the fleece.