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USDA Zone 3b planting calendar

In USDA Zone 3b, the average last spring frost is around 05/20 and the first fall frost around 09/19, giving roughly a 121-day growing season. Plant cool-season crops from late winter; warm-season crops after the last frost.
Last frost ~05/20 First frost ~09/19 ~121-day season 11 NOAA stations

Frost dates are the median across 11 NOAA weather stations in Zone 3b (1991–2020 normals, 50% probability). Range: last frost 05/14–06/05, first frost 09/08–09/29. For your exact town, use the ZIP tool.

The year in Zone 3b

What to plant now (August)

Radishes
Sow for fall harvest

All crops in Zone 3b

CropStart indoorsTransplant / sowSow for fall
TomatoesApril 19 – April 26May 24 – June 7
PeppersApril 8May 27 – June 10
EggplantApril 12 – April 26May 31 – June 14
BasilApril 19May 24 – June 7
BroccoliApril 1 – April 8April 22 – May 6June 10 – June 24
CabbageMarch 11 – March 25April 15 – April 29May 1 – May 15
CauliflowerMarch 25 – April 8April 29 – May 13June 15 – June 29
Brussels SproutsMarch 18 – April 1April 22 – May 6
KaleMarch 11 – March 25April 15 – April 29June 20 – July 4
LettuceMarch 22 – March 29April 19 – May 3June 5 – June 19
SpinachApril 12 – April 26July 15 – July 29
OnionsFebruary 11 – February 25April 15 – April 29
LeeksFebruary 18 – March 4April 22 – May 6
Swiss ChardMarch 25 – April 1April 29 – May 13
RadishesApril 22 – May 6July 30 – August 13
TurnipsApril 22 – May 6June 30 – July 14
BeetsApril 29 – May 13June 25 – July 9
CarrotsMay 13 – May 27May 26 – June 9
PeasApril 8 – April 22June 20 – July 4
BeansMay 20 – June 3
Sweet CornMay 20 – June 3
CucumbersMay 3 – May 10May 24 – June 7
Summer Squash & ZucchiniMay 6 – May 13May 27 – June 10
Winter SquashMay 6 – May 13May 27 – June 10
PumpkinsMay 6 – May 13May 27 – June 10
MelonsMay 6 – May 13May 27 – June 10
OkraApril 29 – May 13June 3 – June 17
PotatoesMay 3 – May 17
ParsleyFebruary 22 – March 1April 26 – May 10
CollardsMarch 11 – March 25April 15 – April 29June 5 – June 19
WatermelonMay 6 – May 13May 27 – June 10
Sweet PotatoesMay 24 – June 7
CeleryMarch 4 – March 18May 20 – June 3
KohlrabiMarch 11 – March 25April 15 – April 29
ArtichokeFebruary 25 – March 25May 13 – May 27
AsparagusApril 19 – May 3
CilantroMay 20 – June 3
DillMay 3 – May 17
OreganoMarch 18 – April 1May 20 – June 3
SageApril 1 – April 15May 20 – June 3
ThymeMarch 18 – April 1May 20 – June 3

Fall bulb planting in Zone 3b

Planted in fall after the first frost, for harvest the following summer — a separate calendar from the spring/fall-harvest crops above.

CropPlant cloves (fall)Harvest
GarlicSeptember 23 – October 7Following summer

Last verified 2026-08-28. Frost: NOAA NCEI 1991–2020 Climate Normals. Zone: USDA 2023 Plant Hardiness Zone Map (PRISM-derived). Planting rules: UNH Extension, Johnny's Selected Seeds, UGA Extension.