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Old 27-07-2014, 05:38 PM posted to uk.rec.gardening
FrankB FrankB is offline
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First recorded activity by GardenBanter: Feb 2013
Posts: 65
Default Salvia blight?


"Sacha" wrote in message
...
On 2014-07-24 00:58:12 +0000, FrankB said:

"Sacha" wrote in message
...
On 2014-07-23 15:03:18 +0000, FrankB said:

"FrankB" wrote in message news:...
I've been growing a Salvia 'Patens' in a 2L pot and it was doing fine
until
the last 2 weeks some worrying dark brown spots and blotches have

started
to
appear on the leaves, young and old. Any ideas?

Are you keeping it pretty dry and watering only when necessary? Let it
drain between watering, too and don't let the leaves get splashed with
water through which sunlight can burn them.

Hi Sacha.

I have 2 photos of the problem.


https://www.flickr.com/photos/120747...ostream/lightb
ox/


https://www.flickr.com/photos/120747...ostream/lightb
ox/

As regards watering I rang up a nursery today where a guy who seemed to

know
about Salvias told me that this problem may arise if they are not

watered
enough and that I should not let them get dry in the pot. I originally
suspected it was a fungal problem, but he didn't think so and I can see
nothing on the web that suggests that Salvias are affected by fungal
diseases..I've ruled out siun scorch as some of the leaves higher up the
plant have started to show symptoms whereas I always water with the

nozzle
of my can close to the soil surface, so upper leaves don't get splashed.


I showed your photo to Ray and he agrees with your nurseryman that,
unlike most (!) you've let them get too dry but repeats that you
shouldn't over-water and let them drain between waterings. We have a
large Salvia leucantha Santa Barbara and a Salvia guaranitica in two
separate pots and they get a splash once a day. There's a fine balance
between giving them sufficient water and killing them with too much in
this hot weather. Our pots are terracotta and very tall sort of Ali
Baba shaped things. We can see from the outside roughly where the damp
level is. But if you're using plastic pots, as yours seem to be, it
would be a good idea to raise them a little to let the water drain
freely, just to make sure your watering regime doesn't go too far the
other way.


Yes, it is in a 2L plastic pot. The pot is resting on potting compost so
presumably any excess water will drain away into that.

I've picked off all the affected leaves which is about half those on the
plant. It continues to make new flower spikes and the vigour of the plant is
encouraging. I did give it a tomato feed about 2 weeks ago and it may just
be a coincidence but that's when the symptoms first started to appear. By
the way I'm getting lots of seed from spent flowers. Do you know if Salvia
Patens comes true from seed?