In the garden this week: Lettuce and dahlias

Anyone for lettuce? If you're itching to get sowing as the days lengthen, turn your thoughts away from tomatoes – they'll only get triffid-like on windowsills before it's warm enough to plant them out. But lettuce for fresh spring salads can be sown now. Look out for 'Reine de Glaces', a fine choice for early sowing, which is pale-green, crisp, frilly and tasty. Cover with a cloche or – even better – grow in the greenhouse, at least at first. Bring on the dahlias If you have overwintered dahlia tubers (or just bought new ones), start them into growth. Pot up in large pots and grow on in a cool, frost-free place. In my garden, they don't stand a chance if planted straight out – slugs nip off every hopeful sprout – but grown on and planted out in May, they make robust plants better able to withstand their attentions.