What to do in December

Prune Birches (Betula) Japanese maples (Acer palmatum) and ornamental and edible grapevines this month as they are prone to bleed from pruning cuts in the months after Christmas.
Purchase seed potatoes at the end of this month. It may seem early but tubers will store well in a cold frost free place and should be ready for chitting from January.
Check the see grease bands or barrier glues are still sticky and protecting fruit trees from winter moth.
Place cut Christmas trees in water to prevent premature needle drop always position trees away from heat and water container grown trees regularly.
Prune establish blackcurrants. Blackcurrants fruit best on younger wood so remove up to 3rd of older branches at the base.
For early tender stems force rhubarb by covering with a forcer or a dark coloured bucket.
Prune freestanding apple and pear trees. Apply winter wash
Pests such as mealybug, scale insects and glasshouse whitefly remain active on indoor and greenhouse plants. Check regularly and control promptly to reduce damage and spread.
Garlic can still be planted in deep well-drained soil and in pots.
In mild dry weather cut lawns if necessary to 3/4 to 1 1/2 inches long.