Answer: The brown leaves could be caused by salt or sun and wind burn. About once a month I would suggest doubling the amount of water for the roses to flush the salts out of the root zone. If we encounter temps that are in the 110 range increase your watering frequency to three times a week.
Spider mites could also cause the leaves to brown. Hold a white sheet
of paper under a cane while shaking it, if spider mites are present they will
show up on the paper. Washing down your roses at least weekly with a strong
spray of water will not only help to eliminate the mites but will help the
roses through the hot weather. If that fails to dislodge the mites then you
should use a miticide.
Best wishes with your roses!
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