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Seasonal Planting Calendar

Updated May 2026 · 0 plants · 0 actions

Zone 2bNorthern TierZone 3bNorthern TierZone 4bMountain WestZone 5bMidwestZone 6aMidwestZone 7aMid-AtlanticZone 7bUpper SouthZone 8aSoutheastZone 8bPacific NorthwestZone 9aCalifornia MediterraneanZone 9bGulf Coast / SouthwestZone 10aSubtropical

Midwest gets 148 frost-free days — enough room for one full warm-season crop and a quick cool-season second act. September is the editorial lens for what to start, transplant, and direct-seed now. Pick a USDA zone above to compare.

Zone 5b in September

☀️ In-season3 weeks to first frost
September is prime growing season for Midwest — your 148-day window means every warm week counts. Transplant tomatoes and peppers once nights are reliably above 50°F, succession-sow lettuces every 2 weeks, and plan for first frost 3 weeks from now.

About Zone 5b

USDA Zone 5b (Midwest) has an average last frost of May 10 and first frost of Oct 5, giving roughly 148 frost-free days. Last frost mid-May. Memorial Day is the safe transplant rule of thumb. Sources: U of I Extension, Purdue Extension & Midwestern gardeners.

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