It turns out that when you follow the instructions given on a gardening programme, things actually grow. I wish I'd been more diligent about photographing these from the same vantage points every seven days. I vow to improve my documentary techniques, to complement the bloke's gardening notes.
In the three trays of sweet pea pots above, you can see that nearly all the Spencers and moderns came up in the two trays on the left. Sadly, the old-fashioneds in the tray on the right didn't fare as well, although a few are catching up now since they seem to be slower to germinate. Perhaps their tray simply got too wet, because the ground underneath the cold frame isn't level.
I spent a significant portion of last weekend hunting down nice straight elder branches, stripping them and making climbing frames for the sweet peas. I planted them on Sunday afternoon and checked them anxiously last night. So far they've weathered the predations of passing snails and slugs, but I suspect a bowl of beer in the centre of each teepee might be in order for the next couple of weeks. I don't know how to keep the cats from drinking it, however.