Predicted impacts of climate change on crops—including yield declines and loss of conservation lands—could be mitigated by exploiting existing diversity within crops. Here we examine this possibility for wine grapes. Across 1,100 planted varieties, wine grapes possess tremendous diversity in traits that affect responses to climate, such as phenology and drought tolerance. Yet little of this diversity is exploited. Instead many countries plant 70–90% of total hectares with the same 12 varieties—representing 1% of total diversity. We outline these challenges, and highlight how altered planting practices and new initiatives could help the industry better adapt to continued climate change.