Hi all - I recently potted a new John F. Kennedy rose that is about 3.5 feet
tall and has multiple canes with a few buds which are about to open. A lot
of the leaves, especially at the top of the canes, are curling at the edges
and have a white cast to them, which from my online research looks just like
powdery mildew. What would be the best way to treat that in a potted rose?
Should I remove all the infected leaves and cut back the canes, or try to
treat it with fungicide first? It would be a shame to cut it back
severely -- the bush has a nice upright shape and strong, healthy canes.
Also, I read that neem oil shouldn't be applied when temps are over 90
degrees; does that mean it shouldn't be used in hot weather at all, or just
not actually applied to the leaves when the temp is above 90? Thanks in
advance for any assistance.

Rhonda
Richmond, VA
USDA Zone 7


*********
Basic human psychology is one of my subroutines.

g'day natty,

not a rose person or even a flower person, but maybe you could try the
milk recipe listed on our site on the remedies page.

also something to consider if the root system of a plant is healthy
then the plant will be healthy and mush more about to resist disease,
so look to drainage/watering of the plant (might be getting too wet),
probably alos available suitable nutrients, and above all and this is
all i know about roses they like a lot of sun or equivalent
substitute. also being in a well ventilated area could help.

just some ideas



snipped
With peace and brightest of blessings,

len

--
"Be Content With What You Have And
May You Find Serenity and Tranquillity In
A World That You May Not Understand."

http://mywebsite.bigpond.com/gardenlen2/

I have a JFK (not potted) it is 8 years old and has never had powdery
mildew problem, in otherwords it is not prone to powdery mildew.

First, treat the rose with a fungicide. then see that the rose is in
full sun, and with good air circulation. Never wet the folage direct,
especially in the evening. Presistent powdery mildew is as much
inviremental as anything else. Only cut the canes back if the wood
shows signs of disease.

Enjoy your rose, I have 26 of them-SodB!

On Sun, 28 May 2006 06:31:46 GMT, "Natty Dread"
wrote:

Hi all - I recently potted a new John F. Kennedy rose that is about 3.5 feet
tall and has multiple canes with a few buds which are about to open. A lot
of the leaves, especially at the top of the canes, are curling at the edges
and have a white cast to them, which from my online research looks just like
powdery mildew. What would be the best way to treat that in a potted rose?
Should I remove all the infected leaves and cut back the canes, or try to
treat it with fungicide first? It would be a shame to cut it back
severely -- the bush has a nice upright shape and strong, healthy canes.
Also, I read that neem oil shouldn't be applied when temps are over 90
degrees; does that mean it shouldn't be used in hot weather at all, or just
not actually applied to the leaves when the temp is above 90? Thanks in
advance for any assistance.

Rhonda
Richmond, VA
USDA Zone 7


*********
Basic human psychology is one of my subroutines.