Your December Garden

The first of the winter months is here, bringing with it the shortest day of the year. With colder temperatures and less daylight hours, this is a month often best spent cosying inside, dreaming about your New Year gardening plans.

There are, however, plants to enjoy outside and inside the home plus delicious vegetables to harvest for warming soups and casseroles.


What to Enjoy Now

Flowering in time for Christmas: Schlumbergera (Christmas Cactus)

Gardening is as much about appreciating the beautiful now as planning and planting for the future. Enjoy these plants in your garden and home this month:

Flowering Now

  • Cyclamen – both the showy, bedding varieties and the hardy perennial types, like garden jewels
  • Winter-flowering Hellebore varieties, like Helleborus niger HGC ‘Wintergold’, Helleborus x ericsmithii HGC ‘Shooting Star’ and Helleborus x ballardiae HGC ‘Merlin’
  • Winter-flowering shrubs: Sarcococca confusa (Christmas Box), Hamamelis x intermedia (Witch Hazel), Skimmia japonica varieties (colourful buds throughout autumn, opening in late winter), Viburnum tinus varieties
  • If the weather is mild, you may be lucky enough to see an early Snowdrop or two!

Fantastic Foliage and Architectural Stems

  • Ornamental grasses
  • Key shrubs and trees: Cornus, Acer palmatum varieties, Euphorbia, Corylus avellana ‘Contorta’ (fantastic twisted stems that look amazing when frosted)
  • Conifers, such as Juniper, Spruce and Fir varieties

Fruit and Berries

  • Ilex (Holly), Pyracantha (Firethorn), Gaultheria, some Skimmia varieties

Houseplants

  • Schlumbergera (Christmas Cactus), Poinsettia, Azaleas, Indoor Cyclamen, Amaryllis


What to Plant Now

Brilliant winter stems: Cornus ‘Anny’s Winter Orange’

So long as the ground isn’t completely frozen, there are a number of winter shrubs that can be planted now – or, planted into pots. In fact, weather permitting, planting deciduous shrubs now gives the roots a chance to get started while the plants are mostly dormant.

What to Plant for Instant Impact

  • Cornus (Dogwood) varieties, Leucothoe and Skimmias

Hillier Tip: Cornus varieties with bright stems, such as Cornus ‘Anny’s Winter Orange’, look great when planted en masse. Try underplanting with the striking black grass Ophiopogon planiscapus ‘Nigrescens’.   

What to Plant for Future Interest

  • Rhododendrons, Forsythia, Prunus ‘Kojo no mai’

Hillier Tip: Variegated varieties of Rhododendron such as ‘Goldflimmer’ give all year round interest.  


Grow Your Own

December is a quiet month for sowing in your allotment or vegetable patch, but a number of delicious vegetables should be ready to harvest.

Harvest Now

  • Leeks, Parsnips, Kale, Rocket, Pumpkins and Squash
  • Main crop potatoes
  • And don’t forget the Brussels Sprouts for Christmas!


What to Do in the Garden

Cold weather may limit time in the garden this month, but there are still a few enjoyable jobs you can do if opportunity presents itself.

Plants to Prune

  • Prune your Wisteria, cutting back any new shoots from the summer to two or three buds
  • Prune Apple and Pear trees
  • Cut back dead stems on your perennials if you haven’t’ already and apply a layer of mulch such as garden compost, manure or bark

Hillier Tip: Avoid pruning the seed heads on your Hydrangea. It’s better to leave them until the spring – not only do they look attractive, but they protect the newly forming buds.

Plants to Move

  • If you have lifted and stored plants in your greenhouse, check that the greenhouse heaters are working

Plants to Protect

  • A number of plants, including Tree ferns, Cordyline and Olives really need extra protection in very cold weather. It is worth having horticultural fleece on standby in December. Fasten it on with clothes pegs for temporary insulation when it turns very cold. Specially designed fleece bags with drawstrings are available in different sizes and are a great option for single specimens, especially in pots

Hillier tip: If horticultural fleece is left on for the whole of the winter, it will likely come undone in gales. It may be detrimental to the plant’s health if it soaks up rainwater, as the moist micro-climate created can encourage fungal growth

  • If you haven’t done already, standing pots on pot feet will protect them from frost damage and stop the roots becoming waterlogged. Be aware that plants in pots are more susceptible to cold weather and may need fleecing even if they wouldn’t ordinarily when growing in the ground
  • Wrap grease bands around fruit trees to prevent overwintering winter moth

Lawncare & Gardencare

  • There may still be patches of fallen leaves to clear up across your lawn and borders – but leave your grass longer now to reduce moss build up

Hillier tip: Raking up leaves is good for your lawn health. But, in your flower beds, you will need to decide whether to keep them leaf free or leave some. Raking up leaves is good for plant health, but is not so good for overwintering insects and birds like thrushes and blackbirds  

Weather Readiness

  • To prevent garden taps freezing over, we recommend insulated tap protectors.
  • Bubble wrap is also useful for outdoor pipes and insulating your greenhouse
  • Keep your paths and driveway safe by having some de-icing salt stored away, ready to sprinkle over any persistent icy patches.


Birds and Wildlife

In the winter months, it is important to offer extra food for birds and a fresh water supply:

  • Frequently top up bird food and choose feed with a high fat content, like suet fat snax. Specially formulated, high energy seed mixes are available as well as specific Robin feed for our winter friends
  • Put fresh water out daily, as it freezes over easily in winter
  • Put up a nest box for added winter shelter, if you didn’t do so already in autumn


Monthly Tool Checklist

Some of the essential garden tools and products we recommend to have ready in your shed.

For winter pruning:

  • Pruning shears, mulch (compost, manure or bark)

For frost protection:

  • Pot feet, bark chips, Coldframe, Mulch, Greenhouse bubble insulation, Horticultural fleece, Sulphate of potash, Tree grease bands

Get ready for spring!

Now is the ideal time to make sure your tools are cleaned, sharpened and oiled ready for the spring. Putting a new edge on secateurs, shears and even spades will give you a head start come March.