Question
I have planted a number of roses in Eureka, CA, over the past three years. The ones in large pots seem to do the best, and can be placed in areas that get more sun than the plants growing closer to the house. My four potted roses are all different types of Grandiflora. All have been doing well until recently. Now one has many yellow leaves that show no other causes of damage.
You've previously said that this could be a result of high heat, or some other factor that would cause the rose stress. "High heat" in Eureka is never higher than seventy degrees! However, this is July, and we have had more than our regular share of " nice" days! Still, having checked for other sources of possible stress, I can find none. The pot is still large enough, well drained, and mulched. No other roses, in pots or older ones in the yard, show this sort of symptom. What should I do?

Answer
You haven't told me what you have been doing
are you feeding it if so what?
Perhaps you are over watering it?
needs to dry out in between watering.
you say they are in pot?
when was the last time you repotted them?

Roses tend to get yellow leaves which drop, this is normal
sometimes they drop because
like you said
some type of stress

too much water
not enough water
assuming everything was fine until recently
I would report

Talk to me....