"Jake" wrote

"Bob Hobden" wrote:

Just noticed there is the first signs of Powdery Mildew attacking the
leaves
of some of my Tuberous Begonias. It's normally an autumn thing but I
assume
this unusually cold wet weather has brought it on early. Everything I look
at in the Garden Centres specifically says not to be used on Begonias, or
it
does when you search the manufacturers web site.
These are some expensive show begonias and some I inherited from my mother
in 1993 so I don't want to lose any of them.
Anyone know what I can use to cure or prevent it spreading?


According to RHS, there are now no effective curative fungicides
available for domestic use anyway. But I BELIEVE that Bayer Fungus
Fighter Disease Control is OK to use on begonias and has some
preventive impact - you should be using it almost as soon as leaves
emerge sort of thing. If the infection is very recent, though, it may
help. I've checked Bayer web site and they don't say "not on begonias"
for this product but suggest you check with Bayer Customer Services to
be sure.

Otherwise it's a case of quick removal of any infected leaves and all
fallen plant matter, drying the atmosphere, creating air flow
(removing some unaffected foliage may mean they're not show worthy
this year but be life-saving for next) and crossing fingers.


I think that contains Myclobutanil and looking at the RHS Advisory Leaflet
it says "Do not use on fuchsias, begonias, asters, solidago and young
seedlings". Similar for anything containing Difenoconazole.

Perhaps I'll try the 1 part (full or skimmed) milk to 9 parts water, or
maybe the Bicarbonate of Soda spray, (1 tbs baking soda, 1/2 teaspoon liquid
soap to 1 gal water) but I think that would need to be tested first on one
plant.

What I can't believe is it has appeared first on the plants that have been
outside for 3 weeks so hardly dry at the roots or lacking in air movement!
--
Regards. Bob Hobden.
Posted to this Newsgroup from the W of London, UK