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When to Plant Snap Peas in San Mateo County, CA

Snap peas have edible pods with plump, sweet peas inside, combining the best features of snow peas and garden peas. They are a garden favorite for fresh eating.

San Mateo County, California is in USDA Zone 10a. The average last spring frost is January 18 and the first fall frost is December 12, giving you a growing season of approximately 328 days.

At an elevation of 277 feet, San Mateo County receives approximately 16.9 inches of rainfall annually with predominantly loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Snap Peas to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Snap Peas successfully. Mulch heavily to conserve soil moisture.

San Mateo County, CA (Zone 10a) Year-round
328 days
Last Spring Frost January 18
328 growing days
First Fall Frost December 12

San Mateo County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (206 days to spare)
Start indoors: Dec 3 Transplant: Jan 21 🍅 Harvest: Mar 18 – May 13
Recommended (50%) ✓ Fits season (209 days to spare)
Start indoors: Dec 7 Transplant: Jan 25 🍅 Harvest: Mar 22 – May 17
Safe Start (90%) ✓ Fits season (156 days to spare)
Start indoors: Feb 10 Transplant: Mar 31 🍅 Harvest: May 26 – Jul 21

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.2″/week
You supply
1.3″/week
Watering frequency 2-3 times/week
Season total 3,810 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Snap Peas needs ~672 GDD — county provides 3,536 GDD Excellent fit

Snap Peas Planting Timeline โ€” San Mateo County, CA

Snap Peas Planting Calendar

Activity When Date Range
Start Indoors December 7 Dec 7 โ€“ Dec 21
Transplant Outdoors January 25 Jan 25 โ€“ Feb 8
Direct Sow January 18 Jan 18 โ€“ Feb 8
Harvest March 22 Mar 22 โ€“ May 17

Plant 1" deep ยท 4" apart ยท Rows 18" apart

Month-by-Month Timeline

MonthActivities
January Transplant Outdoors Direct Sow
February Transplant Outdoors Direct Sow
March Harvest
April Harvest
May Harvest
June โ€”
July โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December Start Indoors

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

55โ€“70 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 10a

Growing Season

328 days

Growing Tips for San Mateo County

Direct sow in early spring as soon as soil can be worked. Provide a trellis 4-6 feet tall. Harvest when pods are plump and snap cleanly when bent.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Level Up Your Garden

Frequently Asked Questions

When should I plant Snap Peas in San Mateo County, CA?

San Mateo County is in Zone 10a with an average last frost of January 18. Plan your Snap Peas planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is San Mateo County, CA?

San Mateo County, California is in USDA Hardiness Zone 10a. The average last spring frost is January 18 and first fall frost is December 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help San Mateo County gardeners in Zone 10a organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for San Mateo County, CA. Local conditions may vary. Last updated: April 2026.