Question
Hello I have a rose bush planted in a very large pot on my balcony.
IT has been attacked by black spots - I have sprayed this but the leaves continue to fall off the bush.
Now I have noticed some white dust-like stuff peppered all over new rose buds.
What is this and how can I help that poor plant?
Thanks


Answer
The spots are a rose disease called black spot and can be helped with a fungicide such as Funginex or Bayers rose and garden spray. This will also stop the mildew which is the grey, powder on the leaves. Just follow the directions on the bottle. Roses just love cool roots and when they are grown in a pot, it tends to make the roots too warm, especially the frail little feeder roots, and this causes the rose to be prone to the problems you have.
Because the rose is in a pot, it needs to be watered well such as drenching it so that the water comes out the drainage holes, then letting it dry for a couple of days and then drenching it again.
Also feed it extra well to compensate for the excess watering which washes away any granular fertilizer. Any slow release fertilizer works really well for any thing in a pot. Plus spray it with a mixture of mixture of liquid fish fertilizer ( see dilution rates on the bottle) this gets food quickly through the leaves. Hope this helps. Lynnette