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Old 04-10-2006, 12:00 AM posted to rec.gardens
Gravelle Gravelle is offline
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First recorded activity by GardenBanter: Oct 2006
Posts: 2
Default Battle with blackspot on Roses.

Is the baking soda just sprinkled on the leaves, or is it mixed with
something else?

Thanks.

"JoeSpareBedroom" wrote in message
...
"Nevermind" wrote in message
...
I am fairly new to Rose gardening and have one hybrid tea rose (Chihuly)
right
now. I have the plant in a large plastic pot where it has been for 2
years, here in
the Dallas, TX. area. For two years I have been removing leaves that
appear
infected, and spraying the top and bottoms of the leaves with the ortho
commercial fungicide (chlorothanonil). I didnt think it was helping much
because
this is a constant battle, having to remove leaves, pick up the dead
ones, spray,
etc... every week... I recently decided to try baking powder (I didnt
have
baking soda), vegetable oil, and insecticidal soap. Mixed the
appropriate levels
of each, and sprayed... Since approximately 1 week, nearly half of the
leaves
appeared infected, and most have dropped off. I want to keep the rose,
but I
want to try and kill this fungus somehow... ill try anything. I even
thought that I
would wait until fall temps dropped and I would pull the plant out of the
original
container, remove the soil completely (bare root) and cut back the
topgrowth.
Bleach the container, discard the soil, and lightly spray the outside
surface of the
rose plant with a 1/10 mixture of bleach or soak the plant, etc.. for a
brief
period of time. What can I do? Anything?



1) Insecticidal soap will serve no purpose in the spray you made, and
might mess with the pH, which IIRC is the reason baking soda is sometimes
effective.

2) When you say "large plastic pot", how large, in height and width?

3) Spend some big money on a really big box of baking soda. Baking powder
is not a viable alternative.

4) Describe the placement of the pot, relative to sun, wind, other plants.