Simple past tense and past participle of winterkill.(verb)
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Use "winterkilled" in a sentence
"Later on, he sent me scionwood from other known hardy varieties which I placed on butternut, and many of these made tremendous growths but were winterkilled the very first winter."
"If the catkins remain dormant when the pistillate flowers bloom, they have been winterkilled, and the bent down reserves have to be called up."
"We had unusually deep snow for lower elevation lakes and as a result, some smaller, shallower lakes and pond may have winterkilled."