USDA hardiness reference

Zone 6

Zone 6 represents an average annual extreme minimum temperature band of -10°F to 0°F. It describes winter cold, not vegetable planting dates.

Colder edge-10°FZone 6a begins here
Subzone split-5°FZone 6b begins here
Warmer edge0°FNext broad zone begins

What Zone 6 tells you

It provides a broad basis for evaluating whether a perennial plant is likely to survive a typical local winter minimum. The “a” and “b” subzones each cover five degrees.

What it does not tell you

How Gardiv uses it

Zone is optional context. The annual-vegetable planner uses your editable frost dates for schedule calculations and keeps the zone out of formulas where it does not belong.