USDA Zone 6b planting calendar
Zone 6b planting calendar and seed planner
This Zone 6b planting calendar pairs the warmer half of the Zone 6 winter band with frost dates for your own ZIP Code. Start with the local climate result, not a fixed month printed for every 6b location.
Quick answer
What does Zone 6b tell you about planting?
Zone 6b covers an average annual extreme minimum of -5°F to 0°F, five degrees warmer than Zone 6a. The letter is useful when checking whether a perennial is rated for local winter cold. It is not a spring frost forecast, a soil thermometer, or a guarantee that annual vegetables can be planted earlier than in a nearby 6a garden.
Zone 6b winter range
-5°F to 0°F
Average annual extreme minimum
Step 1 · Local dates
Find spring and fall frost dates by ZIP Code
USDA Zone 6b does not determine frost dates. Enter the garden's ZIP Code to see the nearby NOAA station and three historical freeze-risk choices. The ZIP Code is used for this lookup and is not saved in a user database.
No account needed. Your ZIP Code is used to find nearby NOAA climate records and is not saved in a user database.
Step 2 · Crop timing
Build your Zone 6b seed-starting calendar
Choose a spring date from the NOAA result above to fill the date field, or enter your own outdoor target. The selected date is only a reference: adjust it for the crop's soil or nighttime temperature needs, your seed packet and the current forecast.
Seed-starting calculator
Find when to start seeds indoors
We count backward from the outdoor planting date using university timing guidance.
Local decision checks
Use this Zone 6b calendar without guessing at dates
- Check 1
Use the USDA 6b band for perennial winter hardiness; do not translate it into a universal last-frost date or a monthly vegetable schedule.
- Check 2
Compare the 6b result with nearby 6a or 7a labels only for the perennial cold-range question. Local frost dates can cross a zone boundary in either direction.
- Check 3
For indoor crops, set the outdoor target after frost, temperature and forecast checks. Then use the seed-starting schedule to count back the reviewed indoor weeks.
How Zone 6b differs from its neighbors
A numbered USDA zone spans 10°F, split into two 5°F halves. Zone 6b is bounded by the adjacent bands below. These comparisons are useful for perennial winter labels; they are not a substitute for a ZIP-specific frost lookup.
What Zone 6b cannot tell you
Two addresses carrying the Zone 6b label can still differ in spring freeze timing, nighttime temperature and soil warm-up. A south-facing urban bed may behave differently from a low, exposed garden even when their mapped winter band matches. Use the ZIP lookup below to see historical NOAA freeze probabilities, select a date as a reference, and count backward for indoor starts. Before planting outdoors, apply the crop's own soil or nighttime threshold and check the live forecast. The zone remains context, not the date engine.
Common question: does Zone 6b have one last-frost date?
No. The hardiness band describes the average annual extreme winter minimum. Spring and fall freeze dates vary within the same zone, so use the ZIP-based NOAA history above and check the current local forecast before planting.
Understand hardiness zones versus frost dates →