• Remember that plants grow very little in winter so make sure you start with good-sized plants and use sufficient numbers of plants for the size of container to make an impact from the start
• Position your container where it will get as much light as possible during the winter months to ensure plant foliage remains green and healthy 
• Water containers carefully in winter, making sure you check the compost regularly as it can soon dry out in mild spells. Smaller plants are more susceptible to over- or underwatering
• It is not necessary to feed container plants during the winter
• Raise containers off the ground on pot feet or bricks to aid drainage and help prevent the freezing conditions that cause pots to crack
• Choose frost-proof terracotta or containers made of plastic, fibreglass or wood. Bubble wrap containers in severe weather to reduce damage to plant roots

• Winter bedding plants: these mainly flower in spring, but cyclamen, winter-flowering pansy, viola, primula and polyanthus will flower intermittently during mild spells in winter. The following can also be used: forget-me-not (Myosotis alpestris), large-flowered bedding daisies (Bellis perennis), wallflowers (Erysimium), Cyclamen persicum (not hardy but will usually last until the new year in a sheltered location)
• Evergreen shrubs: these retain their green leaves through winter and make a good focal point in a large container, or can be mixed with other dwarf shrubs for a variety of foliage and flowers and berries. Try box (Buxus sempervirens), bay (Laurus nobilis), skimmia, euonymus, ivy (Hedera) or Gaultheria mucronata varieties. Ornamental cabbage and kale provide additional foliage interest.
• Bulbs: into newly-purchased containers or hanging baskets, consider planting bulbs for additional spring flowers. When you change to a summer display, the bulbs can be planted in the ground to flower the following spring. Try Narcissus, Muscari, Tulipa or Iris
• Hardy evergreen ferns: use hart's tongue fern (Asplenium scolopendrium), common polypody (Polypodium vulgare) and soft shield fern (Polystichum setiferum) in containers for shady positions
• Herbaceous plants: Heuchera are an excellent choice for their evergreen or semi-evergreen foliage in green or rich plum shades, some with exquisite markings
• Grasses: small evergreen ornamental grasses, such as Carex, combine well with winter bedding to give height and a contrast in texture
• Herbs: use those that are evergreen perennials like rosemary, sage, thyme, lavender and curry plant. All prefer a sunny position. Click here for more information on herbs in containers

Links

10 AGM perennials for containers
RHS Find a Plant