Answer: I don't think your frogs would hurt the plant but they may be an indicator that the area is too moist. Evening primrose (Oenothera) tends to do best in full sun on a lean and somewhat dry soil, so it is possible you have overwatered it. Pests don't usually bother it, but you might give it a close inspection for red spider mites and the like. Transplanting in mid-summer can be tough on any plant, so it may simply be that it has failed to settle in.
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