In The Greenhouse This December

If you haven’t already done so, clean out the greenhouse thoroughly. Wash the glass, the floor and the staging with horticultural disinfectant to kill any overwintering pests and diseases.

Insulate outdoor taps or turn them off at the mains. Pack away hoses that are not required.

Wash and disinfect capillary matting before storing it away.

Protect your poinsettias from cold draughts and allow them to dry out slighty between waterings to make them last well into January.

Work in some manure to greenhouse borders to prepare them for next spring. Leave enough space to add compost later on.

Water plants sparingly to maintain as dry an atmosphere as possible.

Brush heavy snow off the tops of greenhouses and cold frames to prevent the glass getting damaged.

Keep an eye out for aphids overwintering on your plants, remove them by hand or use a pesticide.

Propagate perennials from root cuttings including phlox, oriental poppies and mint.

Top Tip:

Ventilate the greenhouse on warmer days to reduce humidity and the risk of disease.

This Month's Key Tips
  • Check your winter protection structures are securely in place.
  • Prune acers, birches and vines before Christmas to avoid bleeding.
  • Harvest leeks, parsnips, winter cabbage, sprouts and remaining root crops.
  • Reduce watering of houseplants.
  • Insulate outdoor taps and prevent ponds from freezing.