A few roots of mint can be dug up, potted, and forced in the warmth of the kitchen to provide leaves to go with the first new potato crops.

If mint or other herbs (such as lemon balm) have proved invasive, then this is a good time to tackle the problem. A selected clump of roots can be dug up and potted, the pot either being kept on the patio, or plunged into the ground to give the illusion of garden planting. Remaining unwanted clumps can be sprayed with a weedkiller containing glyphosate once green growth appears.

Shrubby herbs in pots (e.g. lavender, rosemary and bay) can be top-dressed with a balanced fertiliser (e.g. Growmore or fish, blood and bone) plus some organic matter, or with fresh John Innes compost (No 2 or 3). Shrubby herbs in the garden do not need feeding - most of them thrive in poor soil.

Pest & disease watch

Covering plants with fleece can protect them from flying pests, as well as from the cold.

Look out for signs of botrytis (fluffy grey mould) on herbs, especially in wet weather.

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