Richardson Gr Sp, CA Frost Dates & Growing Season

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

Last spring frost
Mar 10
~50% chance of frost after
First fall frost
Dec 1
~50% chance of frost before
Growing season
266 days
frost-free stretch
USDA zone
≈ 9b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Jan 9 Mar 10 Apr 13
First fall frost Jan 9 Dec 1 Nov 7
Hard freeze (28°F), median last Jan 15 · first Dec 26

Computed from NOAA 1991–2020 climate normals at the RICHARDSON GR SP 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 Richardson Gr Sp

Computed from Richardson Gr Sp's own frost dates. Click any crop for the full zone-9 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Jan 13 – Jan 27 Mar 17 – Mar 24
🫑 Peppers Dec 30 – Jan 13 Mar 24 – Mar 31
🥬 Lettuce Jan 27 – Feb 10 Feb 10 – Feb 24 Feb 10 – Mar 10
🫛 Peas Jan 27 – Feb 10
🥕 Carrots Feb 17 – Mar 10
🥦 Broccoli Jan 20 – Feb 3 Feb 17 – Mar 3
🥬 Kale Jan 27 – Feb 10 Feb 10 – Feb 24 Feb 10 – Feb 24
🥒 Cucumbers Feb 10 – Feb 17 Mar 17 – Mar 24 Mar 17 – Mar 24
🥒 Zucchini Feb 10 – Feb 17 Mar 17 – Mar 24 Mar 17 – Mar 24
🫘 Green Beans (Bush) Mar 17 – Mar 24
🌽 Sweet Corn Mar 17 – Mar 24
🌿 Basil Jan 27 – Feb 10 Mar 17 – Mar 24 Mar 24 – Mar 31
🧄 Garlic Fall: Oct 20 – Nov 17

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 Richardson Gr Sp's dates automatically after a lookup.

Reading the season in Richardson Gr Sp

With roughly 266 frost-free days, Richardson Gr Sp 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 Dec 1 is late enough that fall planting is a full second season, not an afterthought.

Frequently asked questions

When is the last frost in Richardson Gr Sp, CA?

The average last spring frost in Richardson Gr Sp is around Mar 10, 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 Richardson Gr Sp, CA?

The average first fall frost in Richardson Gr Sp arrives around Dec 1. 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 Richardson Gr Sp?

About 266 frost-free days on average, from Mar 10 to Dec 1. That comfortably fits long-season crops like melons and winter squash, plus spring and fall plantings of cool-season vegetables.

What USDA zone is Richardson Gr Sp in?

USDA zone 9b 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.