PlantAlong

When to plant garlic in zone 8b

Plant for fall between Nov 20 and Nov 27. That is 1-2 weeks after zone 8b's median first frost, Nov 131. Across most of zone 8b that date falls between Nov 11 and Dec 7.

Why a range: zone 8b is defined by winter lows, not frost dates. Its ZIP codes have median first frosts from Nov 4 to Nov 232, so a single zone date can be weeks off for you. The rule comes from University of Wisconsin–Madison Division of Extension, Wisconsin Horticulture, written for WI and applied here to zone 8b's frost dates.

Last reviewed
Stations
652
ZIP codes
2,535
Photo: Chris F / Pexels
These dates use the typical last frost for the whole zone. Your ZIP code gives a closer answer.
  1. Plant for fallWisconsin
  • Start indoors
  • Plant outdoors
  • Range across the zone
  • Frost-free season (median)
  • Spring frost risk (90% to 10%)
  • Fall frost risk (10% to 90%)
Figure 1. Garlic in zone 8b. Dark bars: at the zone's median frost dates. Pale bars: across most of the zone's ZIP codes. Hatched blue: where the zone's last and first frosts fall.
Fall planting
Nov 201-2 weeks after first frost

Five digits. The calendar is computed on your device.

What each source says, applied to zone 8b

The same frost dates give different answers depending on whose rule you follow. These are all the published rules we hold for garlic, worked out at zone 8b's median frost dates.

Table 1. Garlic rules from every source, at zone 8b's median last frost (Mar 17) and first frost (Nov 13).
SourceWhatRuleZone 8b median
Minnesota3Plant for fall1-2 weeks after first frostNov 20 – Nov 27
Wisconsin1Used abovePlant for fall1-2 weeks after first frostNov 20 – Nov 27
Texas A&M (E-502)4Plant for fall4-6 weeks before first frostOct 2 – Oct 16

Frost across zone 8b

  1. Last spring frostmedian Mar 17
  2. First fall frostmedian Nov 13
  • Frost-free season (median)
Figure 2. Frost dates across zone 8b, from 652 NOAA stations matched to 2,535 ZIP codes.

Sources

  1. University of Wisconsin–Madison Division of Extension, Wisconsin Horticulture, Garlic, Allium sativum, Rev: 10/2023. Retrieved 2026-11-02.
  2. NOAA National Centers for Environmental Information, U.S. Climate Normals 2020: U.S. Annual/Seasonal Climate Normals (1991-2020), 2021. Retrieved 2026-11-02.
  3. University of Minnesota Extension, Fruit and Vegetable News blog, Tips for garlic planting season, Page shows October 15, 2026; URL path says 2021/10 (unresolved). Retrieved 2026-11-02.
  4. Texas AgriLife Extension Service, The Texas A&M System, Texas Home Vegetable Gardening Guide (E-502), 2/09. Retrieved 2026-11-02.