has witheredUsed for plants that have withered or dried up. 枯れる can also describe a voice becoming hoarse. しまった adds a sense of completion, finality, or regret, such as “has unfortunately withered.”
JA: 旅行から帰ると、ベランダの花が枯れてしまった。
EN: When I got back from my trip, the flowers on the balcony had withered.