Autumn is the best time to plant garlic and overwintering onions. Here is how to time it, set depth and spacing, and mulch for a safe winter.

Most failed sowings come down to a few avoidable errors: seed buried too deep, compost kept too wet or too dry, the wrong soil temperature, and seedlings crowded before they have a chance.

A practical checklist for first-time vegetable seed starters — trays, mix, timing, light, watering, potting up and hardening off — plus the small details that decide whether seedlings thrive.