Climate change is threatening crop yield, impacting global food security and trade. Crop wild relatives may contain climate adaptations that can be quickly introduced into cultivars, especially in perennial tree crops that use rootstock. Identifying climate resilient genotypes that can potentially be used as alternative rootstock is imperative to mitigate the impacts of climate change. Here, we used whole genome sequence data of 59 Northern (Juglans hindsii) and 39 Southern California black walnut (J. californica) adult trees to: (i) determine predicted adaptedness to future climate based on landscape genomic models, (ii) explore their adaptedness if used as rootstock in existing walnut orchards, and (iii) identify potential future planting sites within existing croplands. Northern California wild black walnut has the highest predicted adaptedness to the future climate of Northern and Central California walnut orchards, while Southern California black walnut has the highest predicted adaptedness to Southern and Central California walnut orchards. Southern California black walnut has high adaptedness to the future climate of more existing cropland than does Northern California black walnut. If walnut farmers wanted to test new rootstock sources for their existing orchards or convert their farmland into walnut orchards, this study informs the exploration of such ideas. We demonstrate how landscape genomic tools can be utilized in agricultural contexts as first steps in identifying climate adapted genotypes.