St. George, UT Frost Dates & Growing Season

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

Last spring frost
Mar 14
~50% chance of frost after
First fall frost
Nov 10
~50% chance of frost before
Growing season
241 days
frost-free stretch
USDA zone
8b
2023 hardiness map
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Feb 27 Mar 14 Apr 6
First fall frost Nov 22 Nov 10 Oct 27
Hard freeze (28°F), median last Feb 27 · first Nov 20

Computed from NOAA 1991–2020 climate normals at the St George station (3 km from central St. George). "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 St. George

Computed from St. George's own frost dates. Click any crop for the full zone-8 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Jan 17 – Jan 31 Mar 21 – Mar 28
🫑 Peppers Jan 3 – Jan 17 Mar 28 – Apr 4
🥬 Lettuce Jan 31 – Feb 14 Feb 14 – Feb 28 Feb 14 – Mar 14
🫛 Peas Jan 31 – Feb 14
🥕 Carrots Feb 21 – Mar 14
🥦 Broccoli Jan 24 – Feb 7 Feb 21 – Mar 7
🥬 Kale Jan 31 – Feb 14 Feb 14 – Feb 28 Feb 14 – Feb 28
🥒 Cucumbers Feb 14 – Feb 21 Mar 21 – Mar 28 Mar 21 – Mar 28
🥒 Zucchini Feb 14 – Feb 21 Mar 21 – Mar 28 Mar 21 – Mar 28
🫘 Green Beans (Bush) Mar 21 – Mar 28
🌽 Sweet Corn Mar 21 – Mar 28
🌿 Basil Jan 31 – Feb 14 Mar 21 – Mar 28 Mar 28 – Apr 4
🧄 Garlic Fall: Sep 29 – Oct 27

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 St. George's dates automatically after a lookup.

Reading the season in St. George

With roughly 241 frost-free days, St. George gardens fit long-season crops — melons, winter squash, sweet potatoes — with room left for spring and fall rounds of greens and roots. The first frost around Nov 10 is late enough that fall planting is a full second season, not an afterthought.

Frequently asked questions

When is the last frost in St. George, UT?

The average last spring frost in St. George is around Mar 14, 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 St. George, UT?

The average first fall frost in St. George arrives around Nov 10. 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 St. George?

About 241 frost-free days on average, from Mar 14 to Nov 10. That comfortably fits long-season crops like melons and winter squash, plus spring and fall plantings of cool-season vegetables.

What USDA zone is St. George in?

USDA zone 8b 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.