In article ,
says...

In article ,
"Jeff Layman" writes:
|
| We had (have? - read on) "Amethyst" for several years. It grew very well
| and flowered brilliantly (without any pruning) for 5 years. Then, suddenly,
| in May 2006 its flowers started to curl up before opening properly. When
| the leaves appeared, they too started to curl up and appear dry.

Fairly typical symptoms of some sort of root-rot.

What's the drainage like? We have had some VERY wet weather.


Regards,
Nick Maclaren.

They grow on the edges of swamps/wetlands in the wild so whether our wet
winter will cause it I have no idea, but some sort of phytophora root
rotting fungus does sound likely, possibly even honey fungus. the only
other thing I can think of is if it were near a path to which weedkiller
has been applied, or near a drain that may have had something nasty go
down it (its roots having got into the drain.)

To answer the other query Wisteria are root grafted, ie a piece of
seedling root about 4" long is attached to a shoot from the desired
plant, there is no possibility of the root throwing its own shoots so any
new growth is the same plant you had originally. So it will not matter
how far down you look you are unlikely to see the join.
You do not have to graft Wisteria to get a good plant, they can be done
by both summer and winter cuttings but its not easy or reliable (but
better than my grafting skills) It is seedlings that are to be avoided,
they are grown in large quantities to provide root stocks and are cheap
to buy so sometimes the unwary think they are getting a bargain (and
sometimes of course they do as the resulting plants can be good as well
as bad)
--
Charlie Pridham, Gardening in Cornwall
www.roselandhouse.co.uk
Holders of national collections of Clematis viticella cultivars and
Lapageria rosea