Question
I have an area with 7 pink knockouts that have been thriving for 4 years. This
August the leaves of only one bush browned quickly and it was gone. There
were no signs on the other bushes until October  and now the browning is on
two other bushes. Looks like I could lose them all. What would you suggest? I
live in Kansas City  Missouri.

Answer
It is hard to tell exactly what is causing the problem without seeing the rose bush but there are a few situations that will cause a rose to go brown. The first one is that the temperature was high for a little time in the summer and it heated up the soil which damaged the roots. Another thing that will cause what you describe is fertilizing or spraying when the temperature is hot. Some roses will re-act severely to certain sprays.Inspect under the leaves and see if you can see and very tiny insects that are making minute webs. Also check the roots and see if they have any bumps or nodules on them even if they are mushy. All these symptoms will cause the rose to die. Can you get back to me and give me more information if these things I have described are not the cause? Hope this helps.