I've got an Olive that's been on my south facing roof garden for a couple of years and appears to have caught some kind of black spot.
The inner leaves are one by one developing small black spots. Maybe one or two per leaf. Over several days the leaves turn light green then yellow and fall off.
In March I did 'hide' it between two conifers for protection against some heavy wind and rain for about 5 days (quite a shady damp place) after which the symptoms appeared.

It's a healthy tree - doubled in size in 2 years (about 1m tall) and has got many flower buds that are about to bloom.
With all this leaf drop (about 5-10% so far) I'm worried about it lasting much longer.
Am about to treat with a fungicide (Dithane945) - is that a good idea?

On 18/6/08 21:02, in article , "Packs"
wrote:

I've got an Olive that's been on my south facing roof garden for a
couple of years and appears to have caught some kind of black spot.
The inner leaves are one by one developing small black spots. Maybe one
or two per leaf. Over several days the leaves turn light green then
yellow and fall off.
In March I did 'hide' it between two conifers for protection against
some heavy wind and rain for about 5 days (quite a shady damp place)
after which the symptoms appeared.

It's a healthy tree - doubled in size in 2 years (about 1m tall) and
has got many flower buds that are about to bloom.
With all this leaf drop (about 5-10% so far) I'm worried about it
lasting much longer.
Am about to treat with a fungicide (Dithane945) - is that a good idea?



Before doing anything make sure it's draining properly and that the compost
isn't waterlogged. I'm assuming it's in a pot so if that is the case, raise
it up on bricks or something and make sure the pot has adequate drain holes,
too. Damp and shade aren't olive friendly. Think of their normal habitat,
stony, well-drained and sunny!

--
Sacha
http://www.hillhousenursery.com
South Devon
(new website online but not completed - shop to come and some mild tweaking
to do!)

Sacha wrote:
On 18/6/08 21:02, in article , "Packs"
wrote:

I've got an Olive that's been on my south facing roof garden for a
couple of years and appears to have caught some kind of black spot.
Am about to treat with a fungicide (Dithane945) - is that a good
idea?



Before doing anything make sure it's draining properly and that the
compost isn't waterlogged. I'm assuming it's in a pot so if that is
the case, raise it up on bricks or something and make sure the pot
has adequate drain holes, too. Damp and shade aren't olive friendly.
Think of their normal habitat, stony, well-drained and sunny!

OP has south-facing roof garden. I doubt that shade is a problem! You
could be right about the compost; it's not unknown for drainage holes to get
blocked.

No idea about how well the Olive tolerates Dithane 945, or any other
fungicide for that matter.

--
Jeff
(cut "thetape" to reply)

On 19/6/08 10:58, in article ,
"Jeff Layman" wrote:

Sacha wrote:
On 18/6/08 21:02, in article , "Packs"
wrote:

I've got an Olive that's been on my south facing roof garden for a
couple of years and appears to have caught some kind of black spot.
Am about to treat with a fungicide (Dithane945) - is that a good
idea?



Before doing anything make sure it's draining properly and that the
compost isn't waterlogged. I'm assuming it's in a pot so if that is
the case, raise it up on bricks or something and make sure the pot
has adequate drain holes, too. Damp and shade aren't olive friendly.
Think of their normal habitat, stony, well-drained and sunny!

OP has south-facing roof garden. I doubt that shade is a problem! You
could be right about the compost; it's not unknown for drainage holes to get
blocked.

In terms of shade I was thinking of him saying he'd tucked it among other
plants for shelter, so I wondered if that meant shade, too.

No idea about how well the Olive tolerates Dithane 945, or any other
fungicide for that matter.

I don't know what they're sprayed with - if anything - in Greece, Italy,
France etc. Someone living there might know.

--
Sacha
http://www.hillhousenursery.com
South Devon
(new website online but not completed - shop to come and some mild tweaking
to do!)

When sheltered it was in a fairly shady spot - next to a west facing shoulder height wall between two tall conifer trees.
It's up on two bricks so drains freely (but not when it was in the sheltered spot). Also it's got lots of gravel in the base of the pot.

Well I've applied a bit of the Dithane945 - so see what happens.
Also I won't water it for a couple of weeks.

If it's about to flower could it still be over watered/damp?
Almost all new growth this Spring has been blooms.

On 19/6/08 17:16, in article , "Packs"
wrote:

When sheltered it was in a fairly shady spot - next to a west facing
shoulder height wall between two tall conifer trees.
It's up on two bricks so drains freely (but not when it was in the
sheltered spot). Also it's got lots of gravel in the base of the pot.

Well I've applied a bit of the Dithane945 - so see what happens.
Also I won't water it for a couple of weeks.

If it's about to flower could it still be over watered/damp?
Almost all new growth this Spring has been blooms.



Just put it in the sun, make sure it can drain if it rains and leave it be!
Gravel wicks up moisture so it's just getting wetter. When it's dormant it
might be a good idea to re-pot it with broken crocks or large pebbles, piled
huggermugger under its roots - big broken up stuff, not neat small stuff
that holds wet compost.

--
Sacha
http://www.hillhousenursery.com
South Devon
(new website online but not completed - shop to come and some mild tweaking
to do!)