December Gardening Tips
Early in the Month
Overgrown deciduous hedges can be cut back hard while they are still dormant.
Put netting over winter greens to keep pigeons off. Alternatively sitting a realistic model of a large owl on a post adjacent to your crop also deters them.
New deciduous hedges can be planted now. Cut the new plants back hard after planting.
Avoid getting greenhouse plants too wet, they are much better kept on the dry side over the winter.
Feed flowering houseplants weekly using a liquid fertiliser.
Avoid walking on frozen lawns, as this damages the grass leaving brown footprints until the spring.
Float a rubber ball, or a chunk of polystyrene, in your pool to prevent it from freezing over completely, or buy a pool heater.
Put your sawn off Christmas tree in a stand which holds water, as this aids needle retention.
Feed garden birds and make sure that water is also readily available.
Frost and wind can loosen newly planted shrubs and trees. Check and re-firm them.
Alpines and other seeds needing a cool period in order to germinate can be sown now.
Whitloof chicory roots can be dug up, potted and brought into the warmth and darkness in order to produce “chicons”.
Geranium seeds can be sown now- if you have suitable conditions to grow them on.
Go through the greenhouse every week and dispose of dead leaves and flowers.
Repair fences while climbing plants are still dormant.
Plant new trees and shrubs when weather conditions are favourable.
Try to hoe off weeds whenever you see them, as this will pay dividends later.
Grow some sprouting seeds in jam jars for an easy, nutritious addition to meals.
Cut some berried holly for house decoration and keep it in a bucket in a cold greenhouse to prevent birds from taking the berries.
Take root cuttings from herbaceous plants like phlox, oriental poppies, and Japanese anemones.
Ventilate the greenhouse on sunny days to reduce the risk of fungal infections.
Later in December
Winter is a good time to plan next year’s crops and ornamental displays.
Prune free- standing apple and pear trees. Prune greenhouse grapes, when all the leaves have fallen, cutting back the side shoots to one bud long Christmas pot plants – remember Cyclamen and Azaleas like it cool, Poinsettias need more warmth.
Clean pots, seed trays and service tools ready for the new season’s work.
Cover a sheltered area of veg. garden with clear polythene to warm it up for early spring sowings.
Sow onions suitable for exhibition, like Robinson’s Mammoth or Kelsae in a heated greenhouse.
Winter wash dormant fruit trees, using Vitax Winter Tree Wash, or Growing Success Winter Tree Wash, for a clean start next spring.
Start winter digging on the veg. garden but keep off very wet soil – it ruins the structure.
If snow is expected encircle vulnerable conifers with hoops of wire to hold branches in place that could, otherwise, be bent outwards by heavy falls.