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X Cupressocyparis leylandii - The conifer you either love
or hate, is under severe threat - not from suffering neighbours with
weedkiller or axes, but from a small aphid which has found a great place
to feed - totally unhindered in the dense cover of well cared for
Leylandii hedges. Our own observations would seem to suggest that they
prefer a good feed on the golden form of Leylandii - Castlewellan Gold
being the most common. A good specimen of
Leylandii can grow as much as 3ft (1 metre) in a year - and onwards and
upwards after that. Thoughtlessly planted - and often miss-sold - they
have become a fighting ground for neighbours after being recklessly
planted by un-knowledgeable owners. True - as a screening plant, or
dense hedge - they have been a boon for those wanting a bit of privacy
in their garden, but all too often the Leylandii has been neglected,
resulting in out of control hedges, or worse, sixty feet high trees
which do little to endear neighbours to each other!
The 'perfect' Leylandii hedge on left
shows no signs of damage. The Clipped hedge on right showing severe
infestation symptoms. There is sufficient re-growth on this to look for
at least partial recovery.
Irresponsible planting and aftercare, has even
resulted in legislation. Legislation aimed at curbing the problem, but
made cumbersome by stupid drafting, and little thought to
implementation. Where Leylandii is a problem, a quick remedy is
required, not procrastination by local officials as is often the case.
However, the little Cypress Aphid has come to the
rescue - maybe only temporary - by sucking the sap out of these
loathsome trees. 'Death by bug' may not become a complete reality, for a
cold winter may kill or reduce the Cypress aphid population. However,
this 'fright' may do much to deter people from planting x
Cupressocyparis in the future.
As with all aphids, it can be controlled if not killed
by insecticide sprays. Herein lies a problem for would-be 'DIY pest
control enthusiasts!
- Firstly, it is not proven that old brown growth
will re-grow. Very doubtful! And in any case this is a little like
closing the gate after etc etc etc.... The brown patches mean
dead plant tissue. The aphid will have had its fill and moved either
further along the Leylandii hedge, or of to a neighbouring stand of
fresh foliage.
- There would be considerable cost involved in most
cases. The little 'Ready to Use' Bug gun will not go far in this
particular fight.
- There is a considerable problem with the actual
spraying of a large hedge - not least from the health point of view
of yourself - and also your neighbours!
Maybe at last, the solution has been found to this
problem. And, it is a problem of considerable magnitude to those
neighbours who are not 'owners' - yet are almost helpless to do anything
to stop their own garden being used as a reservoir for the thirsty and
hungry
Leylandii.
No hope of any re-growth on this Leylandii hedge.
The RHS has concluded that this might be the worse
outbreak for 25 years! Not a bad conclusion considering that there are now many
thousands more Leylandii in existence than there were 25 years ago!
Aphids are normally found once gardening proper
starts! Easter is the normal time for gardening activity. It is also the
time when gardeners everywhere are amazed to find aphids sucking away at
young plant growth. Those aphids are normally quite visible. However,
for the aphid sucking away in the dense confines of the Leylandii hedge,
no problem of being found out. In any case, the feast may have been
going on for a couple of months with the mild winters we have
experienced. So the damage is first noticed with the brown patches on
the Leylandii hedge. Too late for insecticide - the bug has flown!
SE UK seems to be the main problem area, but it won't
be long until the aphids find their way up the M1 - especially if the
milder weather continues.
An insecticide containing imidacloprid and thiacloprid would be our
suggestion. Don't worry about the chemical name - Provado Ultimate
Bug killer contains the ingredients and is available at any good
garden centre. It has a systemic action, so is taken up into the sap of
the Leylandii, not simply used as a 'contact' killer. (It does have a
contact effect, but it is the ability to be taken into the plant's sap
system which is the important aspect.) BUT not on hedges where you cannot control the spray or
drift. Get a professional to do the work - or start afresh with a new
type of hedge! Some say that the Leylandii will perhaps recover from all
but the worse attack. |
