Trees & shrubs

shrub plantingPlanting and moving

Bare-root deciduous hedging plants, trees and shrubs become available this month. They need to be planted promptly, before they dry out. They can be heeled into the soil for a short period if conditions are not suitable for planting.

It is an ideal time to plant roses. Avoid planting in areas where roses were previously growing otherwise new introductions may suffer from replant diseases (rose sickness).

You can still order and plant containerised trees and shrubs, and large semi-mature specimens for planting later in the winter, when bare-root plants are no longer available.

Protect newly planted trees, hedges and shrubs from wind and cold. A temporary netting windbreak is sufficient where there is no natural shelter. Straw, bracken, or something similar can be used to pack around deciduous plants and protect them from frost. A wooden frame with clear polythene stretched over it can do a similar job without blocking light from evergreens, but don’t let the polythene touch the foliage, as condensation at these points could freeze, or cause rots.

This is also a good time to transplant trees and shrubs growing in unsuitable positions. However, if they are more than a couple of years old, you are unlikely to be able to remove an intact enough rootball to ensure the plant’s survival in its new position, and you may be best advised to leave well alone.


tying in rose climberPruning 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 and Corylus. Exceptions are tender plants, and also Prunus species (e.g. ornamental cherries, plums and almonds), as these are vulnerable to silver leaf if pruned in the autumn or winter. Evergreens are best left until the spring.

Lightly prune bush roses now, if not done already, as reducing their height will prevent wind rock. These plants are generally shallow-rooted and can become loose in the soil if buffeted by strong winds.

Climbing roses should be pruned by now, these are usually done much earlier in the autumn.

Shrubs normally pruned hard in the spring - such as Buddleja davidii, Cornus alba and Lavatera - can be cut back by half now, to prevent wind rock and neaten their appearance.

Over-large trees might be difficult for you to prune, take care not to damage the tree when sawing off thicker branches. It may be best to consult a tree surgeon.

Tie wall shrubs and climbers onto their supports to protect them from wind damage. Any growth that refuses to be trained in this way can be pruned off.


hardwood cuttingsPropagation

Take hardwood cuttings of ornamental shrubs such as Cornus, Euonymus, Forsythia, Hydrangea, Ilex and Salix.

Check hardwood cuttings taken last year. They may need planting out or potting on, and any diseased ones should be removed to prevent this spreading to other plants.

Soft and semi-ripe cuttings taken earlier this year should also be checked for disease.

Tree and shrub seeds and berries can still be harvested and sown, once they are ripe.


tree stakingGeneral maintenance

Check tree stakes and ties are secure and will withstand the winter weather; ensure that ties are not strangling trunks or branches - they may need loosening.

If there is snow in your area, then you may need to brush this off the branches of conifers. Heavy snowfall can splay branches and spoil the shape of the tree.

Place fallen leaves on the compost heap or into separate pens for rotting down into leafmould. Shredding them first with a shredder or mower will help them break down quicker.
 


phytophthoraPest and disease watch

Garden hygiene helps greatly in the prevention of disease carry-over from one year to the next. It is always a good idea to rake up and destroy, do not compost, any infected leaves. Diseases such as black spot on roses, scab on apples and pears and quince leaf blight can all be controlled to some extent in this way.

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.

Holly leaf blight is still uncommon, but can be spread in wet weather.

Rabbits, deer and squirrels can be a nuisance as the weather gets colder, gnawing the bark from shrubs and trees. Placing guards around new woody plants are advisable.

Damage from bay suckers may still be evident, although the pests will have been and gone. However, it is a good idea to remove affected leaves if there are only a few, and to take note to look out for damage next spring (usually around May) - the problem should then be treated promptly.

When pruning trees and shrubs, take the opportunity to examine branches for signs of disease. Small cankers, dieback, and rotten, hollow stumps at the centre of old shrub bases, are best removed early on, before they spread.

Fungi

coral spotToadstools are often visible at this time of year, and many people are concerned that they may be finding honey fungus. Honey fungus fruiting bodies (toadstools) usually appear on, or at the bases of, affected trees.

Similar looking toadstools in beds or lawns are more likely to be harmless saprophytic fungi which live purely on dead material and pose no threat to garden 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), but it is more a sign of unsuitable conditions than a serious pathogen in itself.

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