February and early March, when you need to sow tomatoes – theirs is a long concerto of growth before the fruiting finale – are also, you may have noticed, too cold to do so.

They need 20-25C to germinate, then 10-15C to grow. So if you’re not bringing seed trays into the house, that means an electric propagator in the greenhouse, or – if you’re really retro or/and reducing your carbon impact – a hotbed, either outside, or in a polytunnel. In a hotbed, nature does the heating.