Winter Views

January in Your Garden

The start of the year is always full of promise and optimise for a year ahead.

Essential Jobs

 

  1. Prune Apple and Pear Trees 

  2. Clean greenhouses 

  3. Scrub terracotta pots ready for spring

  4. Dig over any vacant vegetable plots

  5. Disperse worm casts in lawns

  6. Recycle your Christmas tree by shredding or taking to a recycling point

  7. Start forcing Rhubarb

  8. Plan your pottage or vegetable garden sowings and crop placement

  9. Continue to feed and water birds

  10. Protect peaches and nectarines with a polythene shelter to reduce the risk of peach leaf curl

 

 

Flowers

Sowing and planting

Sow seeds of Begonia, Lobelia, Salvia and Pelargonium in a heated greenhouse or propagator to provide early plants.

Sweet peas can be sown this month. Sweet peas sown earlier in the autumn can now be potted on taking care not to disturb the roots too much. Place them on a sunny windowsill, or on a high shelf in the greenhouse that gets plenty of light.

This is the last chance to sow seeds that need frost in order to germinate (such as native tree and shrub seeds, and alpine plants).

Plant lily bulbs in pots and in borders during mild spells.

Summer bulbs, seed potatoes and onion sets will be available to buy from the middle of the month.

 

Cutting back, pruning and dividing

Cut off old leaves of hellebores that produce flowers from ground level to expose the flowers.

Cut away some Iris unguicularis leaves to expose the flowers.

Root cuttings can be taken now. Papaver (perennial poppies), Verbascum (mullein), Acanthus and Phlox are suitable examples.

Start cutting back grasses and other perennials left for winter interest. Alternatively you can leave them a few more months to provide cover for wildlife.

In mild areas, and during dry spells, you can still lift and divide herbaceous perennials. This will increase stocks, and revive tired or poorly flowering clumps.
 

 

General maintenance

Rake up any winter debris and leaves off your borders to keep them tidy. Clear up any weedy beds ready for mulching in the spring.

Collect leaves that have blown over alpine beds as these plants are easily smothered. Bare patches can be covered with gritty compost.

 

Containers

Keep tubs and containers tidy, cutting back and removing debris regularly. They can be mulched with compost or grit. Grit is aesthetically pleasing, and will reduce the surface puddling that can occur when light composts are beaten into a solid ‘cap’ by raindrops.

Some pots - particularly those sheltered by eaves or balconies - may need watering. Check the compost (at a hand’s depth) to see if it feels dry. Aim to keep pots moist (not too wet), but do not let them dry out.

Raise patio containers onto feet or bricks, if you have not done so already, to avoid them sitting in the wet.

 

Tender plant care

Even in mild areas, tender plants that cannot be left outside with protection should really be taken into the greenhouse or conservatory by the beginning of this month. In cold areas, you are best moving things inside much earlier, in the autumn.

In cold spells, protect non frost-proof containers (terracotta pots for example) with bubble wrap, hessian or fleece, to prevent them cracking. Grouping the pots close to a south-facing wall may provide additional protection to the most vulnerable ones

Ensure protective straw or fleece is still in place on tender plants overwintering outdoors.

 

Trees and shrubs

Planting and moving

Plant roses, but avoid areas where roses were previously grown as this can lead to problems with replant diseases.

Continue to plant bare-root deciduous hedging plants and trees. Stakes should be put in place before the rootball to avoid damage to the roots.

Move established deciduous trees and shrubs, provided the ground is not frozen or waterlogged.

Take note of the most vibrant dogwoods (Cornus), Salix and white-stemmed Rubus shrubs for a display of coloured stems.

Seek out scented winter shrubs, such as Hamamelis ,Sarcococca and Chimonanthus, when visiting gardens open to the public, or in garden centres, and consider planting them for a winter display.

 

 

Winter maintenance

Check tree ties and stakes on established plants. Replace, tighten or slacken them where necessary.

Firm back newly planted trees and shrubs if they have been lifted by frost heave or strong winds.

Protect newly planted trees, hedges and shrubs from cold winds and frosts. Erect a temporary netting windbreak if there is no natural shelter. Thick dry mulches will protect the roots from cold, and branches can be covered with straw or bracken, and secured with fleece and ties, to protect them from frost damage. A wooden frame with clear polythene stretched over it does a similar job for evergreens without blocking the light, but don’t let the polythene touch the leaves, as condensation could freeze or cause rots.

If there is snow in your area, then you may need to brush it off the branches of conifers, climbers and light-limbed shrubs and trees. Heavy snowfall can splay branches, break limbs and spoil the shape of the tree.

Remove weeds from around the bases of young trees.
 

Pruning and training

Pruning and renovation of many deciduous trees, shrubs and hedges can be carried out from now throughout the dormant season. It is easier to see what you are doing when the branches have no leaves. Suitable examples are: Fagus (beech), Corylus (hazel) and roses. Exceptions are evergreens and tender plants (best left until spring), and Prunus species (e.g. ornamental cherries, plums and almonds) as these are vulnerable to silver leaf disease when pruned in autumn or winter.

If your trees are too large for you to manage the pruning alone, then you may need a tree surgeon. Otherwise take care not to damage the tree when sawing off thicker branches.

Prune Wisteria - cut back the sideshoots shortened by summer pruning to two or three buds. Avoid cutting off flower buds.

Tie wall shrubs and climbers onto their supports to protect them from wind damage. Ornamental vines, ivy, Virginia creeper and Boston ivy can be cut back now – it’s a good idea to keep them away from windows, doors, gutters and roof tiles.

 

Propagation

Seeds of berrying trees and shrubs can still be sown - but be quick, as they need a period of frost to break their dormancy. Examples are Sorbus, Cotoneaster and Pernettya.

Take hardwood cuttings of ornamental shrubs such as Cornus, Salix, Forsythia, Weigela, Escallonia, Rosa, Ribes, Chaenomeles and Elaeagnus. Many deciduous climbers can also be propagated in this way (e.g. Fallopia and Lonicera).

Check hardwood cuttings taken last year. They may need planting out or potting on.
 

 

Pest and disease watch

Bracket fungi on trees is visible at this time of year. If the tree is in poor health it is worth calling in a tree surgeon for a professional opinion.

Put rabbit guards around newly planted trees and shrubs to protect the bark from rabbit damage.

Inspect sick-looking box shrubs and holly trees for signs of blight.

Phytophthora root rots can cause dieback on mature trees and shrubs. Wet winter weather and poorly drained soils are likely to encourage this problem on susceptible woody plants.

Coral spot is often noticed once the leaves have fallen from deciduous hedges, shrubs and trees. This problem can be connected with poor ventilation and congested, un-pruned twiggy growth (as found inside clipped hedges).

Check for damage or cankers on deciduous trees while stems and trunks are readily visible. Prune out torn or damaged branches to prevent disease infection

 

Greenhouse, conservatory and houseplants

Houseplant care

Check that light levels are sufficient for houseplants. They will need light to carry on over the winter, and can easily be forgotten in a back or spare room that receives little natural light, or with the curtains left drawn. They are best moved to sunny windowsill until March. Don't leave houseplants on windowsills behind the curtains on frosty nights, especially if your windows are not double glazed.

Water houseplants sparingly. Most should be barely moist in winter.

Cut back leggy Hypoestes (polka dot plant), Pilea (aluminium plant), Solenostemon (coleus) and Tradescantia to encourage new growth.

 

Maintain a minimum of 5°C (41°F) to prevent Fuchsia, Pelargonium and other tender plants being killed by the cold. Higher temperatures will be needed for tropical plants.

Fuchsias can be started into active growth by re-potting, increasing watering, feeding (with a slow-release fertiliser such as fish blood and bone), and putting them in a sunny place.

Clivia benefit similarly from a dormant period over winter, with less watering, feeding, and lower light levels.

Cool conditions and regular watering will help keep potted indoor azaleas looking good for longer. Remember to water azaleas with rainwater collected in a rain butt, not with tap water.

 

Bulbs and corms

Indoor forced bulbs used for Christmas displays, and which have now finished flowering, can be left outside in a sheltered spot in the garden, to finish dying down.

Support bulb flower spikes with canes (if necessary).

Pot up Hippeastrum (amaryllis) bulbs, and bring them into active growth with regular watering and feeding. They should give you beautiful flowers for the late winter/early spring.

Place hyacinths in a cool, bright place in the home. If it's too warm, the leaves will elongate and the flowers will fade quickly.

Cyclamen persicum appreciates a cool room with good light. If leaves on cyclamen start to turn yellow, this may be a sign of overwatering. Water from below (into the saucer), and allow the plant to drink for up to half an hour before pouring away the excess water left in the saucer - wetting the leaves can easily result in fungal infections and rotting off.
 

Cacti

Remember that cacti need very little water, and no feeding, over the winter. Keep them barely moist until the spring, when they will be coming up to flowering and will therefore appreciate extra water and feed.


Encourage bushy growth on Christmas cacti (Schlumbergera truncata and S. x buckleyi) by twisting off outer segments from the most vigorous shoots after flowering. These can be used as cuttings if dried and kept warm for a week before potting up.

If your Christmas cactus (Schlumbergera truncata and S. x buckleyi) failed to set flower buds, it may be that the temperature is too high (above 18°C or 65°F), or that the plant is receiving light from an artificial light source after dark. Try moving the cactus into cooler conditions or away from night lighting.

Pest and disease watch

Regularly pick over plants and sweep up fallen debris, to prevent disease appearing and spreading.

Keep an eye out for overwintering pests such as whitefly or red spider mite, and treat accordingly. Nooks and crannies, and the bark of woody houseplants and vines, can harbour mealybugs and scale insect nymphs.

Gardeners Digest by Brewin Dolphin with Paul Hervey-Brookes 2021