Question
I leave near Houston, Texas. I planted knockout roses in the front & back of my home.  The back gets the morning sun & the front gets the afternoon sun.  The plants did very well for the frist 8 weeks now I'm seeing many yellow leafs on the plants - more on the ones in back than the front but both have the yellow leafs.  I have not fertilized the scrubs since they were planted.  I watered them faithfully - every other day for the first 2 weeks after they were planted.  We had a recent period of several weeks where we had much rain but then we've had a week of sunshine. With the good weather returning I had the opportunity to check the plants & found the yellow leafs. What is causing this?

Answer
Your problem is a common one especially since many parts of the country are having such weird weather. When a rose doesn't get sun but gets a lot of rain water, the leaves will go yellow and then when the sun returns, especially if it is hot, the flowers will be burnt on the petal edges and the leaves will be brown on the edges. there is another reason but I honestly don't think it applies in your case, and that is too much water will also make rose leaves go yellow. This yellowing of the rose leaves, because of a long spell of rain, is also happening in my garden. I wouldn't worry as in a couple of weeks you will see new green growth and the plant will return to normal. Hope this helps.