Monthly Gardening Advice – December

Monthly Gardening Advice – December


  • If mild the grass will continue to grow if this is the case it may be necessary to give the lawn a further trim. Make sure the blades are set to around 4cm (1.5 inches) high.
  • Once you have completed the last cut make sure the mower is clean and dry before storing. Remember to drain fuel as unleaded petrol doesn’t keep and may cause issues next year when starting next season. Consider servicing the mower and sharpening blades for next year.
  • Continue to rake fallen leaves off lawns so it doesn’t block out light and air to the grass.
  • Avoid walking on the grass on frosty mornings it can damage / blacken the grass.
  • Repair damaged edges or patches with turf.
  • You can still apply autumn lawn food, which is high in potassium and phosphorous and helps to harden the grass and build a strong root system. Re-cut all edges for a crisp clean appearance.
  • Check for water logging this can be rectified now or in spring.


  • Reduce watering of houseplants as light levels drop.
  • Clivia plants do benefit from a rest period over winter months.
  • Check that houseplants are getting enough light – they are best moved to a sunny windowsill.
  • Cacti and succulents need a period of dormancy over winter, keep barely moist and apply no feed. Resume watering and feeding in spring.
  • Plant up hippeastrum (amaryllis) bulbs.
  • Cyclamen prefer a cool room and watered from below i.e. in a saucer not the pot.
  • Poinsettias should be placed in warm room, away from draughts to ensure they last as long as possible.
  • Cool conditions and regular watering (best with water from water butt not tap water) will help keep azaleas looking good for longer.
  • Put indoor Hyacinths in cool room if they become too warm the flowers will finish earlier.
  • If Christmas cacti (schlumbergera) fail to set bud the room may be too warm or the plant is receiving too much artificial light, so try moving the plant to a cooler room nearer the window.


  • Remove fallen leaves from lawns, pond and borders
  • Rise up containers by using pot feed to prevent water logging.
  • Take hardwood cuttings of berberis, buddleja, salix and forsythia
  • Improve clay soils by incorporating organic matter like composted bark and well-rotted farmyard manure (as long as soil not too wet.)
  • Moving trees and shrubs that are growing in an unsuitable position. If they have been growing for several years make sure you remove a large enough root-ball to avoid root disturbance.
  • Protect borderline hardy plants with protective mulch
  • Protect newly panted hedges from wind and cold by using a temporary windbreak.
  • Check that tree ties are secure.
  • Deer, rabbits and squirrels may be a problem in winter months use tree guards to stop them gnawing at the bark.


  • Remove last remaining spent crops and clean and disinfect the greenhouse.
  • Insulation will be needed to keep greenhouse frost free alongside with a heater if not already done.
  • Regularly inspect plants for pest and disease.
  • Invest in max/min thermometer for accurate monitoring of temperature.
  • Don’t forget ventilation may be required in the warm autumn days.
  • Maintain air movement in the greenhouse and conservatory even in the cold to prevent the build-up of fungal disease.
  • Try not to wet the leaves when watering to avoid fungal diseases developing.
  • Remove faded flowers, yellowing leaves and dead leaves to stop the development of disease within the greenhouse.


  • Stake any Brussel sprout stalks that are leggy and venerable to wind rock.
  • Remove any plant debris to help prevent the spread of disease.
  • Dig vacant areas and add organic matter ready for planting next year.
  • Parsnips can be left in the ground until needed.
  • Prune apple, pears, quinces and medlars.
  • Continue to harvest turnip, swedes, parsnips, celery, brussel sprouts and beetroot.
  • Check stored apples regularly.
  • Plant new fruit bushes and trees but delay planting if the ground is waterlogged or frozen.
  • Prune autumn raspberries.
  • Prune red, white currants and gooseberries.
  • Tie in new tiers on espaliers.


  • Clean out birdbaths and bird feeders.
  • Keep birdbaths topped up and ice free.
  • Refill bird feeders, all feeds including peanuts are safe as the breeding season is now over.
  • Start building a hedgehog hibernation box.
  • Coppice hazels and coppice or pollard other suitable trees.
  • Make a leaf pile for hibernating mammals and ground feeding birds.
  • Dig a wildlife pond.
  • Build a compost heap


  • Remove snow by brushing on evergreens, conifers, climbers and light limbed plants to stop splaying and spoiling the shape.
  • Look through catalogues, plan and order seeds for next season.
  • Place fallen leaves on the compost heap or in separate pen for rotting down into leaf mould shredding first or mowing will help speed up the process.
  • Dig bare patches of earth or newly cultivated land to expose many pest larvae and eggs to birds and frost.
    Make sure all the winter protection is in place to help the plants through the worst of the winter weather.

Enjoy your garden and don’t forget to take time and stop and stare at the wonder of nature. Happy gardening!