We have - used to have - four flowering cherries, and the three
remaining all seem to have the same virus the first, 30+-year-old tree
died from.

I have mentioned this before, but now the situation is getting worse.
All the trees look just like the first: beautiful blossom, apparently no
problem, then serious dieback just after blossoming.

The advice at the time was to prune out the affected branches (which in
this case is the ends of nearly all branches), then spray with a
fungicide. But also that pruning in spring is disastrous, because that
is how the virus enters. So when can I do it?

And which fungicide might be best?

And, finally, is the disease now resident in the garden?

Thanks for any advice...

--
Klara, Gatwick basin

On Sat, 20 May 2006 08:47:27 +0100, Klara
wrote:


We have - used to have - four flowering cherries, and the three
remaining all seem to have the same virus the first, 30+-year-old tree
died from.

I have mentioned this before, but now the situation is getting worse.
All the trees look just like the first: beautiful blossom, apparently no
problem, then serious dieback just after blossoming.

The advice at the time was to prune out the affected branches (which in
this case is the ends of nearly all branches), then spray with a
fungicide. But also that pruning in spring is disastrous, because that
is how the virus enters. So when can I do it?

And which fungicide might be best?

And, finally, is the disease now resident in the garden?

Thanks for any advice...


AIUI, all prunus species including cherries suffer from silver leaf
disease, the fungus Stereum purpureum. The leaves get a silvery
appearance and then die, and the branch dies back, and eventually the
whole tree goes. The fungus enters through open wounds such as pruning
cuts etc. so it is recommended that any pruning be done while the tree
is in full growth, i.e. in the summer, so that the wounds heal
quickly. Infected branches have brown or purple stains within the
wood. If you find such a stain, cut back a further six inches and look
again. Repeat until you see no stained wood, and you may, just may,
save the tree.

Spraying with fungicide won't do any harm, but if the fungus is in the
tree already, I would think only a systemic fungicide sprayed onto
healthy foliage would stand any chance of success.

One of my older books says owners of trees with silver leaf disease
are liable to prosecution if they don't remove the offending branches
and burn them. Whether this is still true, I don't know, but it
indicates how seriously the disease was once taken. If it got into
commercial plum or peach orchards, for example, it could be
devastating.

More than that, I can't tell you.


--
Chris

E-mail: christopher[dot]hogg[at]virgin[dot]net

AIUI, all prunus species including cherries suffer from silver leaf
disease, the fungus Stereum purpureum. The leaves get a silvery
appearance and then die, and the branch dies back, and eventually the
whole tree goes. The fungus enters through open wounds such as pruning
cuts etc. so it is recommended that any pruning be done while the tree
is in full growth, i.e. in the summer, so that the wounds heal
quickly. Infected branches have brown or purple stains within the
wood. If you find such a stain, cut back a further six inches and look
again. Repeat until you see no stained wood, and you may, just may,
save the tree.

Spraying with fungicide won't do any harm, but if the fungus is in the
tree already, I would think only a systemic fungicide sprayed onto
healthy foliage would stand any chance of success.

One of my older books says owners of trees with silver leaf disease
are liable to prosecution if they don't remove the offending branches
and burn them. Whether this is still true, I don't know, but it
indicates how seriously the disease was once taken. If it got into
commercial plum or peach orchards, for example, it could be
devastating.

More than that, I can't tell you.

Thanks, Chris. I was afraid the news would be bad ... but I suppose I
have nothing to lose (except perhaps my health) if I spray with
fungicide.


--
Klara, Gatwick basin

On Sun, 21 May 2006 12:14:10 +0100, Klara
wrote:



Thanks, Chris. I was afraid the news would be bad ... but I suppose I
have nothing to lose (except perhaps my health) if I spray with
fungicide.

I think an important point relating to your question about the disease
now being 'resident in your garden' is to make sure you burn or
otherwise dispose of, any prunings, dead wood etc, as this harbors the
disease and acts as a source for future infections. Leaving it in a
heap for beetles or whatever to live in or composting it is definitely
not recommended.


--
Chris

E-mail: christopher[dot]hogg[at]virgin[dot]net