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. There are contractors who specialise in
moving established mature specimens, but they are not cheap. For more
information, RHS members can contact the Members’ Advisory Service, and
non-members can try the local Yellow Pages.
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.
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 greenwood cuttings taken earlier this year should also be
checked for disease.
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.
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. Roses are generally shallow rooted and
can become loose in the soil if buffeted by strong winds.
Climbing roses should be pruned now at the very latest, and should
preferable have been 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.
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.
Tree and shrub seeds and berries can still be harvested and sown,
once they are ripe.
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.
Pest & 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 (i.e. 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.
Toadstools 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.
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.
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), but it is more a sign of unsuitable conditions than a
serious pathogen in itself.
Holly leaf blight is still uncommon, but can be spread in wet
weather.
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.