GardenBanter.co.uk - View Single Post - cultivated rhododendros : spreading threat?

Stewart Robert Hinsley · 27-05-2010, 05:36 PM posted to uk.rec.gardening

In message ,
writes
In article ,
Eddy wrote:

Along comes a neighbour yesterday with fear writ large all across her
brow and she warns us we had better cut every single flower off once
the petals have fallen OR there'll be rhododendrons everywhere and local
farmers will be furious with us!

There are no other rhododendrons in gardens in this area, though
largely, I suspect, because most of this area is more alkaline than
acidic. We are fortunate in that our little patch is quite acidic.
Could it be that the fear of cultivated rhododendrons in this area has
resulted from the fact that people can't grow them here and are ignorant
of them?

It's only Rhododendron ponticum that's a problem (only two other species
are recorded from the wild in the UK, and neither is at all common) -
other rhododendrons aren't a problem.

No. It's a result of the media hysteria. If rhododendrons don't
grow well locally, they won't naturalise - and acidity is only one
of the factors that they need. Outside SOME parts of the far west,
and a FEW parts of the south, even R. ponticum will have trouble
when faced with real competition. Despite claims, its spread is
NOT limited by the fact that "it hasn't got here yet", but by the
fact that it won't spread to the relevant locations.

I'm not in the extreme west, but Rhododendron ponticum is moderately
widespread in the wild around here - by my field records about as
widespread as ramsons or butterbur.

On the other hand, outside the extreme west one might want to worry more
about Buddleia davidii and Cotoneaster simonsii, or even Ribes
sanguineum and Syringa vulgaris.

Regards,
Nick Maclaren.

--
Stewart Robert Hinsley