December is a good time to saw Alpines from seed. To protect them from extra wet you can put a sheet of glass over the sown area. Alternatively, You can put the seeds in the fridge, for sowing next spring.
Faded herbaceous perennials can be cut back and added to the compost heap or can be left until spring comes. You can still lift and divide herbaceous perennials into mild areas and during dry spells. Papaver (perennial poppies), Verbascum (mullein) and Phlox are the most suitable plants for taking root cuttings this month.
Bark chip mulch can reduce splashing effect from Helleborus niger (Christmas rose) blooms.
Clear up weedy beds and prepare them for spring mulching with well-rotted farmyard manure or mushroom compost. Apply a mulch to protect plants that are borderline hardy.
Check on your garden tender plants for the damage especially after storms.
Raise patio containers onto feet or bricks to avoid them sitting in the winter wet.
Large tubs should be covered with bubble wrap, hessian or fleece to save them from cracking and insulate in winter. Keep your tubs and containers tidy by cutting them back and removing debris regularly. You can mulch them with compost.
It would be better to bring your garden tender plants and pots into the greenhouse or conservatory as expecting even colder weather.
Finish clearing your garden beds and borders, especially leaves and debris from alpines to save them from dying. Cover bare patches with gritty compost to encourage the re-growth of surrounding clumps.
Working in plenty of bulky organic matter, such as composted bark can be really helpful if you want to improve garden drainage of heavy clay soils.
Look out for Botrytis (grey mould) on herbaceous plants, and Hellebore leaf spot on Hellebores, remove affected growth.
Watch out for downy mildew and leaf spot on winter pansies. Also, crown rot and brown rots (sclerotinia) on died down perennials. Daffodils can succumb to fungal problems, such as narcissus leaf scorch.
Antirrhinum rust and delphinium black blotch, as well as sclerotinia, will lay dormant and re-infect plants when they come up the following year. You should replant new specimens in another place if the problem is severe.
Be aware that many diseases will overwinter in the soil, or on plant debris.
Protect newly planted trees, hedges and shrubs if the cold winds and frosts are present. Roots can be protected with thick dry mulches and branches can be covered with fleece.
A wooden frame with clear polythene stretched over it can save evergreens without blocking the light. Be aware that the polythene can’t touch the leaves, as condensation could freeze or cause rots. Putting rabbit guards around newly planted trees and shrubs can protect the bark from damage.
This month you can continue to plant bare-root deciduous hedging plants and trees. Plant roses by avoiding areas where they were previously grown as this can lead to replant disease.
To protect wall shrubs and climbers from wind damage tie them onto their supports.
Fagus (beech), Corylus (hazel), and roses pruning and renovation can be carried out from now throughout the dormant season. Any pruning of Acer and Betula should be completed before the end of the year to avoid bleeding of sap from cuts leaving evergreens and tender plants until spring.
Prunus species (e.g. ornamental cherries, plums and almonds) can’t be pruned in autumn or winter as they are vulnerable to silver leaf disease.
Take hardwood cuttings of ornamental shrubs such as Berberis, Buddleja, Salix, Forsythia, Ligustrum and Rubus. Fallopia, Lonicera and other deciduous climbers also can be propagated by taking cuttings. Last year’s hardwood cuttings may need planting out or potting on.
Pine (Pinus) or fir (Abies) tree hold their needles for longer than the traditional Norway spruce (Picea abies). Avoid placing your Christmas tree near sources of heat. If you want your tree to last longer stood them in a bucket of water and saw off the bottom 5-7.5cm (2-3in) of the trunk to allow the tree to drink freely.
Protect tender deciduous trees and shrubs from frost by packing the branches with straw or bracken and securing this with fleece and ties. Replace, tighten, slacken or remove tree ties and stakes if needed. Remove weeds from around the bases of young trees.
Brush the snow off the branches of conifers, climbers and light-limbed shrubs and trees. Heavy snowfall can hardly damage your trees. Netting should help to protect holly berries from the birds leaving some uncovered for winter wildlife.
Pests and disease watch is very important in winter. Holly leaf blight can spread in wet weather. It is always helpful to rake up and throw away infected garden leaves.
Black spot on roses also can be controlled in this way. Do not compost such material because diseases can persist in compost heaps and re-infect mulched plants.
Look out for damage from bay suckers next spring (usually around May) – the problem should then be treated promptly.
Wet winter weather and poorly drained soils are encouraging Phytophthora root rots on mature trees and shrubs, woody plants.
Coral spot can be a problem if poor ventilation and congested, un-pruned twiggy growth are present. Do not be surprised to see some rabbits and squirrels in your winter garden.
Avoid walking on the lawn on frosty mornings because it can damage the grass and leave brown footprint-shaped marks. Do not forget to continue removing fallen leaves from your lawn and use the mower to keep the lawn in trim If the weather is mild.
Make sure that your mower cut is around 2-4 cm (1-1.5in) to prevent turf stress.
Repair damaged lawn edges or patches with turves cut from other areas of the garden and re-cut all lawn edges to crisp up the appearance of the garden.
Be aware of the signs of waterlogging in wet weather. Laying stepping-stones through muddy lawn can be helpful for easier access. Too much water can cause even bigger problems such as Fusarium patch (snow mould) or Algae which is usually present because of poor drainage or excessive shade on your lawn.
Ice is very harmful to fish and other pond life. Make sure that you are keeping ponds from freezing over. You can use special pond heaters or make a hole by holding a saucepan of hot water on the pond surface.
You can use nylon strings strung across the edges of the pond to deter hungry herons from fishing. It should be at least 15cm (6in) from the ground and 15cm (6in) in from the edge of the pond.
Raking out fallen leaves or shaking off those that have gathered on protective netting is still important this month as well as repairing any leaks in your pond.
Thinking about decorating your home and garden? Do it yourself! Have some wonderful time with your family and create some winter installations together.
You can treat garden timber structures with wood preservative and stain if the weather is dry.
Remove algae from paths to prevent them from becoming slippery.
Winter is a good time of the year to install some water collection equipment such as water pipes and drainage. Be careful and make sure that your standpipes and irrigation lines are well drained. Put lagging around outdoor taps to enable using throughout the winter.
Clean and dry all your garden equipment before storing. Drain out any fuel first to avoid problems in springtime.
Add lights and power points to sheds and outhouses to enjoy and be aware of all your garden advantages in winter. The small effort can lead to big joy!