Gardening in the coldest month

In January the full force of winter is with us and the weather can restrict gardening. Wet and frozen soil is difficult to dig and cultivation now can damage soil structure, so it’s a month to consider the year ahead, plan for summer and browse seed catalogues, working outside only when the days are more clement. It’s also a time to enjoy the more visible bird life, exposed by lack of leaves and the signs of the new years growth. By encouraging birds into your garden to feed and drink now, they will help reduce the numbers of insect pests, slugs and snails throughout the year.

In the garden

Hazel catkins of lambs' tails

Hazel catkins or lambs’ tails, ceridwen, CC BY-SA

Not all in the garden is bleak and grey. Winter bulbs are emerging. Snowdrops and winter aconites nod, luminous, amongst the fallen leaves. The common snowdrop, Galanthus nivalis has narrow, bright green leaves and bell like white flowers but it is only one of a number of varieties in many flower sizes, heights and shapes that fascinate galanthophiles, the snowdrop enthusiasts. Winter aconites have buttercup yellow flowers, surrounded by a ruff of bright green stem leaves. Both quickly multiply in drifts in moist soil, can be scented and are beneficial for pollinators.

The small Algerian iris, Iris unguicularis appears in January too, it has violet petals with white and yellow falls and is very fragrant. Christmas roses, Helleborus open, their subtle, sometimes flecked faces, often bent to the ground, turning them skywards reveals their beauty and their star burst centres. They look perfect amongst bulbs and grow well in heavy clay and partial shade.

Catkins on both hazel and alder open out, lengthening into pendulous lamb tails. Discrete, as they have no need to attract insects, they contain strings of tiny male flowers that dance in the wind, shaking out clouds of yellow pollen to fall in drifts on their female counterparts. Their graceful movements light up the branches of winter trees.

Sarcococca confusa inflorescence

Sarcococca confusa inflorescence, Meneerke bloem, CC BY-SA

Shrubs with winter scent, ensnares the senses, snatching us from grey reality. Their flowers can be insignificant but with few winter pollinators they have to be intense and carry further to attract the active, available insects. Sarcoccoca confusa, Christmas box, is a relaxed, small, evergreen shrub with narrow, pointed, dark green leaves. The delicate, filigree, clusters of creamy white flowers with yellow tips seem to hide along the stems below the leaves, barely visible, but with a startlingly powerful aroma. Daphne bholua ‘Jacqueline Postill’, is an upright, evergreen shrub with waxy, oval, mid green leaves and clusters of pink flowering heads, holding small, yellow tipped stamens within a tubular sheath of petals. It smells of roses. Lornicera x purpursii, winter honeysuckle, is a straggly, twiggy shrub. The white flowers appear before the blue green oval leaves, with pale yellow stamens twisting below small twirling white petals. Chimonanthus praecox, winter sweet, blooms on naked stems. Delicate lemon yellow, translucent petals hang like tiny lanterns from the branches giving off an intense fragrance.

Take root cuttings

Eryngium

Eryngium, Alvesgaspar, CC BY-SA

Root cuttings can be taken any time from late autumn to mid winter when plants are dormant. Choose a vigorous plant, lift it from the soil and wash the roots. Select strong, pencil thick roots and cut them off close to the crown (where he stem and the root meet) making sure to leave plenty of root material on the parent. Replant the parent as soon as possible and firm in. Cut the root into 5-10 cm segments, with a horizontal cut at the upper end and a diagonal cut at the lower end, discard any thin pieces. Insert cuttings into pots filled with cuttings compost-half and half peat substitute and gritty sand, around 5cm apart and with the horizontal top surface just below the soil level. Cover the surface with grit, water lightly and put in a cold frame to develop. Plant individual cuttings in separate pots when they have developed a good root system and show signs of growth.

Coppicing and pollarding

Coppicing is a traditional method of woodland management where a shrub or tree is cut back to just above ground level, allowing it to regenerate strong, straight, fresh growth from the base. Pollarding is a similar method where a tree is cut back to 2 or 3 metres above ground level, resulting in a strong, dense head of growth at that level. Traditionally cut branches were fed to livestock or used as fuel. Both practices keep plants smaller, provide shelter at lower levels and let more light into the understory. Coppiced hazel provides breeding grounds for butterflies such as the pearl-bordered fritillary, stakes for beans and pea sticks. Pollarded willow provides material for charcoal and basketry. Coppicing dogwoods will allow straight, colourful stems for a display next winter. Coppicing Indian bean tree, Catulpa, and forest pansy, Cercis Canadensis will encourage the growth of larger leaves.

Both practices are very simple. To coppice a shrub or small tree cut back all the stems to between 5-7.5 cm of the ground. To pollard a tree such as willow or lime it is traditional to choose a height and cut back to this each year, over place where the smaller twigs or branches grow from will swell into a club like shape. For other trees such as London plane or tulip tree a framework of branches is chosen and cut to the desired length, twiggy stems grow from these and the tree is cut back to this framework regularly.

Sow seeds of native plants that need cold to germinate

Many native trees, shrubs and herbaceous plants need a period of frost or ‘stratification’, before germinating. In the wild, the weathering of the seed coat by frost and rain, triggers the germination process, inducing the embryonic plant to start developing as the weather improves in the spring. This process can be recreated artificially by placing seeds in a moist plastic bag of compost in the fridge for 4-20 weeks before planting in seed compost.

To use the weather as the natural stratification process; fill pots with a half and half mix of compost and horticultural grit, water well then scatter the seeds on the surface. Smaller seeds can be left on the top but larger ones such as acorns will benefit from being pressed into the surface. Label and leave in a cold frame to germinate and pot on as they develop.

Oak, beech, spindle, hawthorn, hazel and wild cherry can all be sown now. Not all seeds will germinate, it is said there is ‘One to sow, one to grow, one for the mouse and one for the crow.’

Plant deciduous hedges

Deciduous hedges grown from bare root whips are cheap and quickly form an attractive boundary that can also provide food and habitat for insects and birds. Whips are twiggy growths with an established root system, around 60cm high. If you can’t plant straight away due to frozen or waterlogged soil, protect the root area by bundling the whips into a shallow hole and covering lightly with soil and sacking. This will prevent them drying out or being damaged by the frost.

As with all planting good soil preparation will encourage healthy growth. Dig a trench around one spade deep and 60-90cm wide and a little way in from the boundary as the hedge will grow outwards on both sides. Remove the roots of all perennial weeds. For a narrow hedge place plants in a single row 30-60cm apart, depending on the species. For a thicker hedge place plants in staggered rows at 45cm with individual plants in each row 60-90cm apart. Spread out the roots, trimming off any damaged sections. Back fill ensuring that the base of the stem where the roots begin to flare out is level with the top of the soil. Shake the plants while back filling and firm down to ensure there are no air pockets, check each plant is upright before the final tamping down. Water well if dry and mulch with bark chips or well-rotted stable manure.

Beech and hornbeam will provide more formal hedges and hold onto some of their brown leaves well into the winter. Hawthorn and blackthorn are the traditional stock hedges, when planted with a small percentage of other shrubs such as dog rose, spindle, guelder rose, wayfaring tree, hazel and privet they form a mixed native hedge with flowers, berries and fruits to enjoy from spring to autumn.

Gardening tasks in January

  • Plan for the year ahead, check the gaps in the garden, think about what plants you might want, whether edible or ornamental, and order seeds.
  • If there is snow, shake it off trees and shrubs to prevent the extra weight bending and breaking branches and stems.
  • Check the condition of any plants needing winter protection.
  • Check the condition of stored tubers and remove any that are rotting.
  • Plant deciduous trees and shrubs.
  • Check the condition, ties and stakes on any newly planted trees and shrubs.
  • Winter prune apples, pears, currants and gooseberries.
  • Take root cuttings from plants such as bear’s breeches, Acanthus, poppy, Papaver, garden phlox, Phlox, mullein, Verbascum, Japanese anemone, Anemone x hybrid, sea holly, Eryngium.
  • Plant deciduous trees, shrubs and hedges when the soil is not too wet or frozen.
  • Wash, dry and stack your seed trays, pots and unused containers ready for the spring planting season.
  • Provide food and water for birds, make sure feeders and bird baths are cleaned regularly and clear of ice.
  • Make a hole in icy ponds with a kettle of hot water to provide oxygen to the water and a place for mammals and birds to drink from. Don’t smash the ice as this can harm some pond living creatures.
  • Repair and treat timber structures, oil timber garden furniture.
Catriona Andrews

CATRIONA ANDREWS

Catriona is a landscape designer and environmental educator. Her work combines naturalistic planting and sustainable practices to create spaces that are sensitive to the environment and welcoming to wildlife. She designs private gardens, community gardens and public spaces and leads courses and workshops on garden and planting design and the environment.