Re: Clematis
Hi Lorraine
You don't say which Clematis you are growing but:
I have the same problem on my Clematis armandii, but it seems to recover
when the weather cools and we get some rain.
the problem for me seems to be made worse if I neglect to keep them
moist enough at the roots, but whatever I do one or
two shoots usually go black each year.....
Mind you if you think mites are sucking maybe our problems are
different. Or you may have the dreaded Clematis wilt, which is a fungal
problem.
Lorraine
It sounds to me much more like clematis wilt than mite attack. Mites do
not usually turn leaves black but cause paling and speckling, often with
some sort of webbing on the underside of the leaves. The creatures are
also quite visible on the underside - clearly so if one has any sort of
maginifying glass to look at them with. - and you would have to have a
very heavy attack indeed to actually kill the shoots. I tend to doubt
your spraying had any effect on the outcome anyway.
The fungus attacks the stems generally about ground level, but often
buried buds at the base will resprout. It doesn't seem to affect the
roots.
A chemical cure for this is to water the clump with Benlate, but organic
growers do not consider this a safe chemical healthwise and they have
found just as good results from piling a mulch of well-matured compost
over the root area. it seems that some fungi normally present in such
compost are antagonistic to the pathogen and destroy it. In addition the
mulch protects those vital basal buds from dry weather and mechanically
discourages attack as I already explained..
I have been growing the large-flowered Clematises for several years with
this mulching regime and have had no sign of wilt, though it is quite
common in my neighbourhood.
--
Tony & Moira Ryan <theryans@xtra.co.nz>
Wainuiomata (near Wellington, capital city of New Zealand)
