On 5/8/13 3:54 PM, Ohioguy wrote:
http://s9.postimg.org/7xum08afz/rose_spots.jpg

I planted 6 rose plants almost a month ago, and all of them seem to
be growing fairly well.

However, 1 of the plants has yellow spots on it. Most of them are on
the lowest leaves, but I believe there are also a few of these on 1 or 2
of the newest leaves.

Is this some disease that I need to be worried about?

Thanks,

Dayton, Ohio


Look at the undersides of the leaves.

If you see white fuzz, then it is mildew. If you see orange blisters
that have opened, then it is rust. Both can be treated with a
commercial fungicide spray. Mix a little liquid soap into the spray;
otherwise, the solution will bead and not wet the infected parts of the
leaves.

If you see neither white fuzz or orange blisters, then the problem is a
lack of one or more nutrients. Blotchy yellowing often means a lack of
iron or zinc in the soil. Iron sulfate is easy to find at most
nurseries and many hardware stores; use 2-3 tablespoons. Zinc sulfate
might be more difficult to find, and roses are usually not sensitive to
a lack of zinc. So try the iron first.

--
David E. Ross
Climate: California Mediterranean, see
http://www.rossde.com/garden/climate.html
Gardening diary at http://www.rossde.com/garden/diary