USDA Zone 6a
Zone 6a winter guide and seed planner
Zone 6a means the coldest temperature in a typical winter averages -10°F to -5°F. That helps with winter survival; use your local frost estimate and crop needs to choose a planting date.
Do not know your usual last spring freeze? Enter your ZIP Code to see a middle estimate and a more cautious date before building the schedule.
Find frost dates →Seed-starting calculator
Find when to start seeds indoors
We count backward from the outdoor planting date using university timing guidance.
What the zone changes
A winter-cold reference
Zone 6a identifies places where the coldest temperature in a typical winter averages -10°F to -5°F. Compare that range with labels for perennial plants, which are plants expected to return for several years.
What the zone does not change
The seed-starting calculation
The calculator counts backward by the number of weeks each crop normally grows indoors. Zone 6a appears for context, but it does not change the date calculation.
Compare nearby zone temperature bands
The letter “a” marks the colder 5°F half of a numbered zone, while “b” marks the warmer 5°F half. A nearby boundary can change the map label without changing your last-frost date.
Why Zone 6a does not have one universal planting date
The same Zone can occur in places with different elevations, rainfall, heat and frost patterns. This page counts from the outdoor date you choose instead of assigning one date to every garden in Zone 6a.
Find warmer and colder spots in your yard →