Pelargoniums must be kept frost-free. In temperate climates, plants grown outside may be saved for the following season by moving them under cover before the first frost is expected, some time in mid autumn. Remove the plants from the ground or containers and shake as much compost from the roots as possible, then trim the stems by half and remove any remaining leaves.
Repot the prepared plants into a box or small pots filed with fresh potting compost. Than water the compost well and leave the box or pots in an airy position for two to three days, while the cut stems seal and so prevent black-leg disease. Store in good light in a frost-free place.
Shoots will soon appear. You need to water them only on fine days when the foliage will dry more quickly and remember to feed them every six weeks during the winter with a well-balanced fertilizer.
During very cold weather keep the plants dry and add extra protection from frost. By spring the shoots will be large enough to be used as cuttings. Alternatively the shoots may potted up separately and grown on for planting out in early summer.