Answer: The most common reasons for brown edges on the petals are diseases and/or insects called thrips. When spring weather is wet, fungal diseases can get a foothold and the results are browning of the petals. If the problem continues throughout the season, it may be due to thrips. Try peeling back the petals of a slightly opened flower to see if you can find these little insects inside the bud. If not, the problem is cultural rather than insect or disease related. Roses need ample water but the soil must drain well or the roots can suffocate. Ailing roots will cause overall problems with the plant, not just with the flowers, but it something to investigate. Hope this information helps you determine just what may be causing the browning on your rose petals.
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