Sep, Oct, Nov, Dec, Jan, Feb
Wet conditions kill more herbs in winter than the cold, so place container-grown perennials such as oregano, thyme, sage and rosemary in a sheltered position against a wall or the side of the house or garage. This will reduce the amount of rainfall hitting the pot by around 25 per cent.
Avoid overwatering container-grown herbs by lifting each pot to assess its weight. If the compost is too dry, the pot will be light, so water the plant sparingly in the morning (not at night as the water may freeze). If the pot is heavy, the compost is too wet, so raise the pot off the ground to allow it to drain.
Trim evergreen herbs into a dome shape (it's a good idea to remove any remaining flowers in the process). This will help to protect them from high winds or snow. Don't prune back too hard, as this will create deep cuts that may not heal.
Raise terracotta pots off the ground, either standing them on bricks, 'pot feet' or on blocks of wood. This will expose the pots' drainage holes, allowing them to drain more freely than if placed directly on the floor. Because water expands when it freezes, this action may also prevent pots from cracking.
Use horticultural fleece or hessian to protect container-grown olives and bay trees from hard frost. As well as wrapping the leaves, it's important to also fix a thick layer of bubble wrap around the pot itself, as the delicate plant roots may be touching the inside of the pot.
Place basil and other tender herbs in a well-lit, frost-free position, but be wary of windowsills as temperatures much below 5°C will kill them. Avoid watering these plants in the evening so they don't have wet roots at night, and harvest basil leaves from the top, not from the sides. Open greenhouses and cold frames during the day if temperatures are warm.