Hi, (from occaisional lurker and poster),

I have a problem with a couple of small holly plants. They've been in the
same place for at least four years. Something is damaging the plants; one
has lost most of its leaves and has large sections of twig going black.
There are also some growths on the twigs. The other appears to be just
beginning to suffer.

If anyone could post a suggested cause and a treatment, I would be most
grateful. I lost another to the same problem last year; dug it up and
burned it in the autumn, and fear these two are going the same way. We have
a huge ancient hedgerow holly tree in the garden, about 70 feet from these
two, I think its OK at the moment..

Ground is clay. Its pretty dry this year. Garden is in Suffolk.

Photographs at this URL:
http://nigelcliffe.photobook.org.uk/...n.php?id=37604

(background in some pictures is discoloured because of flash used to
illuminate foreground)


Many thanks,

Nigel

(ps. email address quoted does not get read, just used for collecting spam,
so don't reply to it, just post back to the group).

"NC" wrote in message
...

Hi, (from occaisional lurker and poster),

I have a problem with a couple of small holly plants. They've been in the
same place for at least four years. Something is damaging the plants; one
has lost most of its leaves and has large sections of twig going black.
There are also some growths on the twigs. The other appears to be just
beginning to suffer.

If anyone could post a suggested cause and a treatment, I would be most
grateful. I lost another to the same problem last year; dug it up and
burned it in the autumn, and fear these two are going the same way. We
have
a huge ancient hedgerow holly tree in the garden, about 70 feet from these
two, I think its OK at the moment..


Your holly appears to be suffering from Holly leaf blight, caused by
infection with Phytophtora illis bacteria. For chapter and verse search for
either term on google and include "RHS advice" in the search line.

There have also been some past discussions here.

That's the good news - the problem identified.

The bad news is that there is no treatment/cure. No fungicides are licensed
for domestic use for this problem.

The slightly better news is that the infection is not necessarily fatal and
steps can be taken to help the infected plants recover and protect others
from infection. See the results of the suggested search for details, but
essentially:

The fungus enters the plant through leaf pores and works its way back.
Hence, cutting back into the green growth behind the dead black growth shown
in you picture removes the infected tissue.

Remove from the plant all such tissue plus all dead leaves lying on the
ground as these harbour the infection and are a source of reinfection.
Another source is water splash from the ground - if possible remove all
leaves 6" or so from the ground to minimise this route.

The problem is likely to be worst in warm damp winters when the water borne
bacteria can travel most freely. The first sign is black spots - pin head
size, as far as I can tell from inspecting the leaves on my own hedge - if
you watch out for those and also the characteristic leaf browning pattern
shown in your top RH photograph, and remove anything suspect you are in with
a chance.

I'm roughly at this stage with my hedge - regrowth IS appearing from the
twigs I cut back into the green and the spread of infection has slowed, but
it is an iterative process through the season as areas infected but not then
showing symptoms begin to brown and drop leaves.

In your specific situation, it sounds like the new/small holly brought the
infection with them. I would be inclined to remove them completely to
prevent their being a source of infection for the ancient hedge.

BTW I would not recommend burning any debris as you are likely to make the
bacteria airborne!


Hope that helps.

pk

"Paul Kelly" wrote in message
...

"NC" wrote in message
...
I have a problem with a couple of small holly plants. They've been in
the
same place for at least four years. Something is damaging the plants;
one
has lost most of its leaves and has large sections of twig going black.
There are also some growths on the twigs. The other appears to be just
beginning to suffer.


Your holly appears to be suffering from Holly leaf blight, caused by
infection with Phytophtora illis bacteria. For chapter and verse search
for
either term on google and include "RHS advice" in the search line.

The bad news is that there is no treatment/cure. No fungicides are
licensed
for domestic use for this problem.

Many thanks for the detailed reply, (much of which I've cut).

Given the size of plants and the severity of infection in one, I think I
should dig up and destroy both. A quick inspection of the old hedgerow
holly showed no obvious symptoms, and it would be a serious loss to risk
that tree. Fortunately material (clippings, compost, etc) tends not to
travel from the infected area of the garden towards the hedge holly, so
risks of transmission are minimised.

RHS website suggests burning as a means of destroying infected material.
I'll look around for a suitable fire and put the remains onto something
that's well alight.

Next is deciding what to replace them with; obviously not another holly.
Pyrocantha is a likely choice - any reason why I should not use that ?


Nigel