Gardening in December

Many a Christmas card depicts a beautiful red-topped poinsettia sat beside a roaring fire. In reality, this would finish your poinsettia flower off fast. While plants need warmth and light, they dislike temperatures above 20ºC and won’t thank you if the mercury dips below 15ºC (poinsettias also sulk by shedding their leaves if exposed to draughts). Keep their compost on the dry side, and only water when the surface has started to dry out because poinsettia plants hate sitting with their feet in the wet.

There’s no finer mid-winter scene than snow carpeting the garden. In most cases, snow is harmless, insulating plants from biting winds and frost. However, it's still work following these simple steps to make sure your garden avoids any lasting damage:

• Use a soft broom to gently sweep heavy deposits from roofs of greenhouses and polytunnels, to prevent damage under the weight.
• Carefully shake the snow from branches of hedges and vulnerable shrubs to prevent them from snapping
• Don’t walk on snow-covered lawns or you risk damaging the grass. 
• When spreading salt to keep paths ice-free, ensure the salt doesn’t drift onto lawns or borders, as it can kill grass and foliage. 
• Lag outdoor taps or turn them off if an isolator is fitted, to prevent pipes from freezing then bursting during a thaw.

Although amaryllis are often planted in autumn, so their towering spikes of showy flowers are in bloom for Christmas, many gardeners also receive these giant bulbs in gift boxes as festive presents.

• Plant into a pot of multipurpose or John Innes No2 compost, so that the top third of the flower bulb remains visible – don’t bury it. 
• Water lightly, place in a bright spot at around 20ºC and it should be in flower in six to 10 weeks. 
• Be aware that flower spikes can become top-heavy when laden with blooms and may require staking.

Do your borders look bleak in mid-winter? Then plan next year’s planting to introduce shrubs that will bloom in the coldest days, while some will fill the air with fragrance.

• Wintersweet (Chimonanthus praecox) loves a sunny spot and will reward you with spicy scent from its waxy yellow flowers. 
• Viburnum x bodnantense ‘Dawn’ is another midwinter wonder, bearing small but highly fragrant pink flowers.
• Witch hazel is a showstopper - try Hamamelis x intermedia ‘Pallida’ for fragrant, wavy, sulphur-yellow blooms.
• The dazzling stems of dogwood are unbeatable for fiery colours – grow Cornus sanguinea ‘Midwinter Fire’ for its vibrant flame-coloured stems.

Find out more about how to create plant beds >

A well-planned winter vegetable plot can yield tasty treats for your Christmas lunch, and brussels sprouts actually taste more flavoursome if they have been exposed to frost.

• Choose the firmest, tightly closed sprouts (usually towards the base of the plant) and snap them off with a quick downward pull. 
• Winter cabbage, leeks and parsnips can be harvested for your festive feast, too. 
• Where brassicas are still cropping, cut off yellowing foliage which can harbour pests and diseases. Keep brassicas covered by netting to deter hungry pigeons.

House plants crave light over winter, so move them to bright rooms, but never leave plants behind closed curtains on freezing winter nights, because temperatures can plummet and cause harm.

Keep leaves free of dust by wiping them with a damp cloth and water sparingly – overwatering is the biggest killer of house plants in winter! Most house plants dislike the dry atmosphere of centrally heated homes during winter, so mist regularly with tepid tap water. Standing plant pots on trays of damp gravel can help to raise humidity.

With December being a quieter month in the garden, it’s an ideal time to carry out routine maintenance.

• If your lawn mower has been put away caked in grass, give it a thorough clean and sharpen the blade (your nearest STIHL approved dealer can do this for you if you’re not sure of the best way to do this or follow our guide). If it’s an electric lawn mower, check the cable for damage. 
• Use a stiff brush to remove soil from tools such as spades and forks, then clean using a rag and WD-40. Sharpen blades on secateurs, shears and axes – the 3-in-1 sharpening tool is a handy option for this. 
• Sludge can build up in water butts, so it’s a good time to drain them down and use the hose to thoroughly clean butts out, before reconnecting to downpipes. They’ll quickly refill from winter rain.
• December is also a good month for tidying sheds.

Get more expert advice on how to take care of your tools >

Coldwater fish are tough cookies and can survive brief spells under a layer of ice, but it’s advisable to keep an area of the pond ice-free as aquatic wildlife needs oxygen. A good method is to float a football or two on the surface before temperatures dip – as the balls move about in the breeze they hinder the formation of ice. If the pond does freeze over, place a saucepan of hot water on the surface to melt the ice and provide a breathing hole. Never smash the ice with a tool or hammer because the shockwaves can harm or kill fish.

Choosing a Christmas tree marks the start of the festivities. Instead of buying a cut tree that’ll be recycled in January, why not invest in a potted tree that can be planted in the garden in the New Year or kept in a big container to bring indoors year after year? Potted trees can be a bit more expensive, but they’ll drop fewer needles, and a living Norway spruce will fill the house with a wonderful Christmassy pine fragrance. Keep living trees well-watered, stand them away from radiators and put trees out in the garden promptly when the decorations come down.

When the ground lies frozen and it’s dark by 4pm, there’s nothing like sitting by the fire, browsing seed catalogues and planning next summer’s displays. Order seed catalogues now and you’ll be in pole position to send off for your chosen flowers and vegetables early in the New Year, when seed supplies are plentiful. UK gardeners are spoilt for choice: Thompson & Morgan, Suttons, Mr Fothergill’s, Unwins, Chiltern Seeds, Kings Seeds and Plant World Seeds are just a handful of must haves for seed growers. Most seed suppliers have their full range available to browse online, too.

It’s easy to create a beautiful container of winter interest plants displaying vibrant buds, berries and blooms. Simply grab a container and fill it with these six star plants for December.

Skimmia Japonica ‘Rubella’ - Grown for its tightly packed panicles of long-lasting, intense red buds in winter, which transform into clusters of scented white flowers in spring, ‘Rubella’ forms the backbone of winter containers and also works a treat when planted solo in plant pots. These evergreens are tough enough to shrug off bitter winters and when they’ve finished putting on a show next spring, slow-growing skimmias are brilliant for plugging gaps in shady borders.

Gaultheria Mucronata - Coloured berries make an ideal substitute for a lack of flower power in winter and Gaultheria mucronata will deliver an attractive show, regardless of what the weather throws at it. These small evergreen shrubs bear vivid berries, from pure icy white to intense shades of purple, set above pointed, prickly dark-green leaves. For best results, grow in a shady spot, although low winter sun will be tolerated.

Hardy Cyclamen - Blooming prolifically in shades of pink, white and red, with bicolours widely available, they blend seamlessly into mixed winter containers. Regular dead-heading is recommended to keep flowers coming. Cyclamen can be prone to rot in wet winters, so grow in well-drained compost, and don’t plant too densely. Leaving space for airflow around plants can reduce the risk of trouble.

Solanum Pseudocapsicum - Commonly known as the Jerusalem cherry or Christmas cherry, the glowing orange fruits of this compact winter star are a must for injecting colour into winter planters. Its fruits, which cling to stems over a long season, resemble little cherry tomatoes but are toxic if eaten, so it’s grown purely as a winter interest ornamental. Jerusalem cherry is a great choice for displays in milder, sheltered regions of the UK.

Heuchera - While heucheras work a treat when planted in drifts in the garden, opt for lighter-leaved varieties that add a new dimension to containers, ensuring that displays catch your eye in low winter light.

Winter Pansies - Winter pansies, traditionally sold under the name universal pansy, are a stalwart of winter containers, providing a  range of colours that’s more commonly associated with summer bedding. Available in a host of colours and shades, they’re excellent value for money and are unfazed by frost, rain, wind and snow. Winter pansies are a top performer for plugging gaps in mixed containers, growing en-masse in pots or planting-up a cheery winter hanging basket. Dainty violas are a great choice for the edges of containers.

For best results:

• Plant all of the above into plant pots or containers with plenty of drainage holes (the tub’s edges can be softened with trailing ivy), filled with multi-purpose or John Innes No 2 compost. 
• Keep containers lightly watered – there’s no need to feed these plants during winter
• Relax and enjoy a splash of colour that won’t run out of steam until spring is around the corner.

The biggest mistake gardeners can make is to grow the same crop in the same place season after season, because it “did well there last year”. In fact, it’s a recipe for encouraging build-ups of soil-borne pests and diseases that are partial to a specific crop. However, the problem is easily resolved using a tried-and-tested technique.

Crop rotation, a system of growing different families of vegetables in different places over a three-year cycle, is simple.  Divide your plot into three sections:

• Brassicas including cabbage, kale, radish and Brussels sprouts
• Root vegetables such as potato, carrot, parsnip and beetroot
• Other crops beans, courgettes, leeks, onions, peas and spinach, for example

Grow each family on a different section over three years and populations of pests and their eggs will diminish, as will the risk of diseases such as club root.

Hollies are remarkably tough. They shrug off pollution, which makes them ideal for creating a hedge to screen a busy road. They’re also unlikely to be flattened by gales in exposed situations, are tolerant of salt-laden wind in coastal areas and are excellent for planting to deter intruders who won’t fancy a brush with its razor-sharp leaf spines.  The berries of this classic evergreen are loved by birds, so if you wat to enjoy sprigs inside your home this month, snip off a couple of the best bits ahead of the festive season before they’re devoured!

 For a holly bush that stands out from the crowd, try the head-turning variegated Ilex aquifolium ‘Argentea Marginata’. Its dark foliage with bright cream margins makes a perfect backdrop for masses of vibrant red berries; it’s an ideal hardy specimen shrub that’ll brighten up a dull corner of the garden all year round.