Answer: The most common causes are sunscald, over fertilization and water stress (over or under watering). If the weather has been hot, the browning can be just a sign of heat stress. It's difficult to know how much is too much water because roses like soils moist but the soil also needs to dry out a bit between waterings. The best approach is to water throughly and then wait 3-4 days and dig down into the soil to see if it is still moist or if it needs to be watered again. Hope this information helps you determine just what the problem might be.
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