In the garden this week: Compost heaps and greenhouses

Keep card in the mix The weather may be cooling, but a good compost heap will go on working in all but the most frozen conditions, so layer it properly for maximum effect. This means adding plenty of dry matter – ripped up cardboard and drier plant stalks – to counterbalance wet green stuff. Give comfrey its final chop and spread it about the layers, too, because it's a great compost activator. Water the lot. Greenhouse gremlins If you have a greenhouse or coldframe and want to move plants into it for winter protection, it needs a really good clean first. I always find frogs, slugs and snails during my greenhouse clearout, which sounds like the makings of a neat ecosystem, but this is not the place for it: even the tiniest slugs can wreak havoc, especially among autumn or spring seedlings. Use hot water and soap, cloths and brushes, plus whatever implements you need to prise the slimy ones from their crevices.