Powdery mildew and roses - December 30th, 2003 at 08:27 PM
My roses seem to have a problem with powdery mildew. What is the best way to treat them, and when?
Re: Powdery mildew and roses - December 30th, 2003 at 09:05 PM
Hi Sarah, 
Here's some info on mildewy roses.
Warm days and cold nights are ideal for causing mildew on roses. Dryness at the roots and poor feeding can also cause mildew. It forms a pale grayish coating on the upper leaf surface and also on the buds. The infected leaves crumple and become distorted. One of the best ways to keep mildew under control is to keep good air circulation around the plants. Pruning to open up the center helps rose bushes Climbers on a closed wall may also not be getting enough air through them and should be pruned more open. Spraying with a fungicide at the first signs keeps mildew under control.
mildew roses
But I bet some of our friends (Barb, Bill, Weezie) know the best way to deal with this. I haven't ran into this yet.
Hope this helps!
Here's some info on mildewy roses.
Warm days and cold nights are ideal for causing mildew on roses. Dryness at the roots and poor feeding can also cause mildew. It forms a pale grayish coating on the upper leaf surface and also on the buds. The infected leaves crumple and become distorted. One of the best ways to keep mildew under control is to keep good air circulation around the plants. Pruning to open up the center helps rose bushes Climbers on a closed wall may also not be getting enough air through them and should be pruned more open. Spraying with a fungicide at the first signs keeps mildew under control.
mildew roses
But I bet some of our friends (Barb, Bill, Weezie) know the best way to deal with this. I haven't ran into this yet.
Hope this helps!
Re: Powdery mildew and roses - December 31st, 2003 at 07:28 PM
Thanks for the info gardengal! 
Re: Powdery mildew and roses - December 31st, 2003 at 08:08 PM
I don't know. Have you done your big pruning yet? In our milder climate down here we tend to prune them back the first or second week of Jan. so they go to sleep for a while. Maybe if you haven't pruned them, give them a good pruning and see if in spring the mildew comes back. If you already have, I would spray now so they'll be healthy in spring...but I don't know if that's right.
Any other rose people out there???
Have you done your big pruning yet? In our milder climate down here we tend to prune them back the first or second week of Jan. so they go to sleep for a while. Maybe if you haven't pruned them, give them a good pruning and see if in spring the mildew comes back. If you already have, I would spray now so they'll be healthy in spring...but I don't know if that's right.Any other rose people out there???