Leavenworth 3SW, KS Frost Dates & Growing Season

The two dates every Leavenworth 3SW garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Apr 19
~50% chance of frost after
First fall frost
Oct 19
~50% chance of frost before
Growing season
183 days
frost-free stretch
USDA zone
≈ 6b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Apr 5 Apr 19 May 4
First fall frost Oct 30 Oct 19 Oct 2
Hard freeze (28°F), median last Apr 9 · first Oct 27

Computed from NOAA 1991–2020 climate normals at the LEAVENWORTH 3SW station. "Safe" means frost past that date happens only about one year in ten. Your exact garden can still run days either way with elevation and terrain — check your own ZIP with the frost date lookup.

Planting windows for Leavenworth 3SW

Computed from Leavenworth 3SW's own frost dates. Click any crop for the full zone-6 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Feb 22 – Mar 8 Apr 26 – May 3
🫑 Peppers Feb 8 – Feb 22 May 3 – May 10
🥬 Lettuce Mar 8 – Mar 22 Mar 22 – Apr 5 Mar 22 – Apr 19
🫛 Peas Mar 8 – Mar 22
🥕 Carrots Mar 29 – Apr 19
🥦 Broccoli Mar 1 – Mar 15 Mar 29 – Apr 12
🥬 Kale Mar 8 – Mar 22 Mar 22 – Apr 5 Mar 22 – Apr 5
🥒 Cucumbers Mar 22 – Mar 29 Apr 26 – May 3 Apr 26 – May 3
🥒 Zucchini Mar 22 – Mar 29 Apr 26 – May 3 Apr 26 – May 3
🫘 Green Beans (Bush) Apr 26 – May 3
🌽 Sweet Corn Apr 26 – May 3
🌿 Basil Mar 8 – Mar 22 Apr 26 – May 3 May 3 – May 10
🧄 Garlic Fall: Sep 7 – Oct 5

Want this for all 50 crops, or as a printable seed-shelf schedule? Use the planting calendar and the seed starting scheduler — both can use Leavenworth 3SW's dates automatically after a lookup.

Reading the season in Leavenworth 3SW

Roughly 183 frost-free days gives Leavenworth 3SW gardeners room for nearly every common vegetable. Warm-season crops go out after Apr 19; a fall garden sown in late summer matures comfortably before the Oct 19 frost.

Frequently asked questions

When is the last frost in Leavenworth 3SW, KS?

The average last spring frost in Leavenworth 3SW is around Apr 19, based on 1991–2020 climate normals. That's a median — about half of years see a later frost, so tender crops are safest going out a week or two after this date.

When is the first frost in Leavenworth 3SW, KS?

The average first fall frost in Leavenworth 3SW arrives around Oct 19. Crops still in the garden need to mature before then, and frost-tender plants need harvesting or protection as the date approaches.

How long is the growing season in Leavenworth 3SW?

About 183 frost-free days on average, from Apr 19 to Oct 19. That fits nearly all common vegetables, though the longest-season melons and sweet potatoes benefit from transplants.

What USDA zone is Leavenworth 3SW in?

USDA zone 6b on the 2023 Plant Hardiness Zone Map. Note that zones describe winter cold, not frost timing — these frost dates are the numbers to plan plantings around.