Christmas has now gone and the New Year has just started so among your New Year resolutions your garden will need to be thought about.  You should now get on with winter digging and tidying up your borders in preparation for spring, removing any leaves that have fallen which can harbour slugs and other pests.
Leave the old growth on anything that is slightly tender to protect them from frost.  Many perennials can be cut back hard, removing old growth to make room for new shoots that grow up in the spring. Firm in any plants that have been lifted by frost.
Early in the month, make the most of bare walls or fences by growing colourful climbers. Continue planting bare root roses, avoiding planting new ones where old roses have been, unless the soil is replaced and conditioned.   Cover tender shrubs etc with fleece.
In the greenhouse remove faded blooms from plants in flower. Avoid over watering annuals and other young plants.  Remove diseased foliage from pelargonium cuttings and if you are unable to get out into the garden when the weather is bad, sow sweet peas in pots or seed trays and germinate them in gentle heat.  Pinch out the tips of seedlings raised from autumn sowings to encourage side shoots to form and make bushy plants.  Also sow seeds in a heated propagator of antirrhinums, begonia semperflorums, cannas, salvias, geraniums, lobelia and verbenas.  Make sure that your pots and trays are clean before sowing.  Examine any gladiolus corms and dahlia tubers you have in store and discard any that are rotting.  Pot up lily bulbs and stand the pots in a sheltered spot.  
In the vegetable garden dig over bare areas, forking in plenty of compost or rotted manure. Place buckets or forcing jars over dormant clumps of rhubarb to encourage stems to form for a delicious early harvest.  Sow peas in a sheltered position also sow broad beans for an early crop.  Sow broccoli, cabbage, greens, onions, peas, turnips, to transplant next month.  Sow carrots, greens and peas at the end of the month.
Prepare a bean trench on the site where you are planning to grow your runner beans in summer. Prune apple and pear trees also newly planted raspberries, gooseberries and currants.  Where pests such as woolly aphid have been a severe problem on apple trees, spray now with a tar oil winter wash. Take care not to splash any on surrounding green plants or paving.   Cover peach and nectarines with polythene to protect them from peach leaf curl.  This needs to be kept on until the end of March.  Try not to let the polythene touch the trees.
If the weather permits and the ground not too wet plant apple and pear trees, deciduous trees and shrubs.  Re-firm the earth around newly planted trees and shrubs after frost.