insideKENT Magazine Issue 64 - July 2017 | Page 156

OUTDOORLIVING
YOUR GARDEN NEEDS THIS MONTH cont.
CHECK CLEMATIS FOR SIGNS OF
CLEMATIS WILT
Clematis wilt is a fungal disease of clematis,
particularly the large-flowered hybrid cultivars.
The fungus causes rapid wilting and, in severe
cases, can kill the whole plant.
The symptoms of fungal infection and
environmental stress can be similar. The
following symptoms are associated with
fungal infection:
• When fungal infection occurs through the
leaves, these wilt and the leaf stalks turn
black. Leaf infection is followed by rapid
wilting of the stems.
• Fungal infection can also occur through
stems. Freshly affected stems show black
discolouration of tissue when split open.
• Young healthy shoots may be produced from
the base of affected stems, sometimes from
below ground.
Control:
• Try to create a suitable root environment by
deep cultivation and mulching, to minimise
root stress.
• If fungal infection is suspected, cut out all
wilted stems back to healthy (non-stained)
tissue and promptly destroy the affected
material to prevent it contaminating the soil.
New healthy shoots may be formed at
ground level.
• Disinfect pruning tools to prevent spread of
spores and avoid transferring infected plant
and soil material to a new area.
• Particularly susceptible cultivars include:
Clematis ‘Henryi’, ‘Vyvyan Pennell’, ‘Mrs N.
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Thompson’, ‘Duchess of Edinburgh’, ‘William
Kennett’, ‘Marie Boisselot/Madame le Coultre’,
‘Ernest Markham’. Clematis 'Comtesse de
Bouchaud'; C. 'Jackmanii' and C. 'Nelly
Moser' are also susceptible.
• Resistant cultivars and species include:
Clematis ‘Avant Garde’, ‘Bonanza’, ‘Confetti’,
C. alpina, C. montana, C. orientalis, C. viticella
(which is tolerant rather than resistant), C.
integrifolia, C. macropetala, C. tangutica.
Pruning out young shoots which are blistered,
and disposing of fallen leaves and infected
fruit will reduce the amount of fungus available
to start infections in the next season.
Unfortunately, this is generally of little value
unless the trees are isolated, because the spores
can be blown for long distances.
TREAT APPLE SCAB
Apple scab is a disease caused by the fungus,
Venturia inaequalis, that spreads by airborne
spores and survives the winter on fallen leaves.
Expect scab marks to appear on leaves from
mid-spring until leaf fall in autumn.
You may see the following symptoms:
• On leaves: Patches of olive-green spots or
blotches appear, wh ich are initially velvety
as they release airborne spores, and then
darkening. Affected leaves often fall
prematurely.
• On young shoots: Infections cause blistering
and cracking that can then provide entry for
the apple canker pathogen.
• On fruit: Black scabby blotches develop and,
as the fruit matures, these restrict expansion
of the skin, leading to distortion and cracking.
Light attacks only damage the skin and eating
quality is hardly affected (though the disease
is commercially very serious, because
growers cannot sell scabby fruit). However,
if the fruits crack as a result of scab they
become prone to fruit rots and will not
store well.
The RHS is a UK charity established
to share the best in gardening. Their
work is driven by a simple love of
plants and the belief that gardeners
make the world a better place.
For more information visit
www.rhs.org.uk