Winter Gardening Calendar
Chief source of massed colour this month is provided by the foliage of evergreens, particularly those variegated or coloured with gold or yellow, or of a fresh green colour. Viburnum bodnantense provides clusters of pinkat its shoot tips and the winter-flowering jasmine makes a prominent display with its bright-yellow flowers. Earliest of the winter-flowering heathers (Erica), which will have been showing promise for weeks, cover themselves with bright flowers, and the first frail blooms of Iris unguicularis can be found nestling amidst their grassy foliage. Take the opportunity of mild spells to prune leafless shrubs in need of attention. Also plant late-arriving shrubs and plants if the ground is not too wet and sticky: if it is, heel the plants in together in a well-drained spot until conditions improve. Tidy established borders, lightly forking over the among the plants. At the same time mix in old mulching material, and add a dressing of manure if available. Feed with bone meal established hedges and areas planted with bulbs. Border plants, such as Japanese anemones, perennial anchusas, and border phloxes, can be propagated from root cuttings taken now. Order seeds for sowing next season; also shrubs and plants to set out in the spring to fill gaps or create new groupings. Cover the soil over plants of doubtful hardiness with straw, bracken, or tree leaves held in place with wire netting, to give extra frost protection in the coming months.
This is often thought of as a completely colourless month in the garden, but there is quite a number of plants that bloom then. The winter-flowering jasmine (Jasminum nudiflorum) is generously spangled with its bright yellow blooms that are continuously produced whenever the weather is mild, and some cultivars of the winter-flowering heather (Erica) are smothered in their tiny blooms, shining even through the snow. In milder areas Garrya elliptica is hung with its long, silver catkins to give a charming display, snowdrops (Galanthus) have appeared in many gardens, and Iris unguicularis opens its lilac blooms throughout the winter months. Towards the end of January, winter aconites (Eranthis hyemalis) begin to flower in the sunshine to provide a touch of sparkling yellow in sheltered spots. More colour is provided by the bark of some trees and shrubs, none more eye-catching than the brilliant crimson young shoots of the dogwood (‘Sibirica’), while the coloured-leaved evergreens, such as the variegated hollies and ivy and the golden conifers, create an impression of sunniness even on overcast days.
Jobs to be done this month include the digging of ground ready for spring sowing and planting, as well as ordering the seeds, shrubs, and plants if this has not already been done. Prune ornamentaltrained on walls and pergolas; also other deciduous trees and shrubs in need of such treatment. If there is a heavy fall of snow, knock it off the branches of conifers and other evergreens; if their shoots are weighed down for long their shape may be spoiled. Make sure that the tender tubers and corms of plants such as dahlias and gladioli are well protected from frost with a mulch.
Although this is often the harshest winter month, cold fails to deter the witch hazels or Daphne mezereum from opening their scented flowers now. The winter-flowering heathers continue to bloom profusely, regardless of frost and snow, while the winter-flowering jasmine and Viburnum x bodnantense open a fresh crop of flowers as soon as each cold spell passes. The first dainty blooms of the dwarf Cyclamen orbiculatum often appear this month and the yellow winter aconites get into their stride if it is sunny. The scented strings of pale yellow Mahonia japonica flowers open at the shoot tips, and the first winter crocuses open wide in any warming ray of sun. The dwarf yellow Iris danfordiae and blue I. histrioides flower, to be joined towards the end of the month by the first few purple blooms of I. reticulata in many places. Retread the soil around newly planted trees and shrubs to firm it again when it dries out after heavy frost. Also push back into the ground any hardwood cuttings of shrubs that have been lifted by frost, and refirm the soil about them. Check posts, pales, trellis, and wires used as plant supports and replace or tighten any that are broken or loose before the plants break into new growth. The end of the month is the time to prune those cultivars of Cornus alba grown for the bright winter colouring of their young shoots, to encourage a new crop the following summer. This is the time, too, to prune allexcept the small-flowered ones, such as Clematis montana, that bloom early. Shear off the old foliage from the rose of sharon ( ), ivies, and other fast-spreading plants before new growth begins.