Boston has been in planting zone 7a, but the winters here are warming. Our coldest annual temperatures have risen by nearly 3 ...

where the hardiness zone is projected ... with northward creeping trees, consult a licensed arborist or your state forestry service. Loading map data... Unlike most plants, trees outlive us.

Since 1951, Boston has been in planting zone 7a, but the winters here ... That shift threatens native plants like sugar maples and birch trees, trees that rely on deep winter chill.