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When to Plant Snow Peas in Napa County, CA

Napa County, California Zone 9b May

Your May gardening checklist

Your Napa County, California garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost February 26
Avg. first frost November 26
Soil temp (4") 74°F
Watering Critical
Pest pressure High
Daylight 14.1 hrs
  1. Start harvesting snow peas

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Coming up in June — start thinking about
  • First harvests: snow peas

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Snow peas are a flat-podded pea variety eaten whole when the seeds inside are still tiny. They are essential in Asian stir-fries and have a delicate, sweet flavor.

Napa County, California is in USDA Zone 9b. The average last spring frost is February 26 and the first fall frost is November 26, giving you a growing season of approximately 273 days.

At an elevation of 449 feet, Napa County receives approximately 35 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Snow Peas during the growing season.

Napa County, CA (Zone 9b) Year-round
273 days
Last Spring Frost February 26
273 growing days
First Fall Frost November 26

Napa County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (173 days to spare)
Start indoors: Jan 13 Transplant: Feb 10 🍅 Harvest: Apr 7 – Jun 2
Recommended (50%) ✓ Fits season (161 days to spare)
Start indoors: Jan 29 Transplant: Feb 26 🍅 Harvest: Apr 23 – Jun 18
Safe Start (90%) ✓ Fits season (147 days to spare)
Start indoors: Mar 5 Transplant: Apr 2 🍅 Harvest: May 28 – Jul 23

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.

Soil Compatibility in Napa County

How your county's soil matches Snow Peas's growing requirements.

Soil pH

Your soil pH (6.7–7.5) is within Snow Peas's preferred range (6.0–7.5).

Soil Texture

The loam soil in Napa County is excellent for Snow Peas — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Snow Peas.

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Snow Peas.

How to Plant Snow Peas

1"
Planting Depth
4"
Between Plants
18"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Snow Peas

6
successive plantings in your 273-day season

Sow every 5.7 weeks. Last sowing by Sep 22 to harvest before frost.

For a dedicated fall crop, sow by Oct 01.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 2,234 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Snow Peas

Snow Peas needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Snow Peas Needs Rainfall You Supplement Action
Jan 7.5" 0" ❄️ Dormant
Feb 4.3" 7.8" 0" ✅ Rainfall sufficient
Mar 4.3" 5.8" 0" ✅ Rainfall sufficient
Apr 4.3" 2.3" 2" 💧 Light watering
May 4.3" 0.8" 3.5" 🚿 Regular watering
Jun 4.3" 0.2" 4.1" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.3" 4" 🚿 Regular watering
Oct 4.3" 1.3" 3" 🚿 Regular watering
Nov 4.3" 3.3" 1" 💧 Light watering
Dec 5.6" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Napa County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Snow Peas Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Snow Peas needs ~920 GDD — county provides 4,384 GDD Excellent fit

Snow Peas Planting Timeline — Napa County, CA

Snow Peas Planting Calendar

Activity When Date Range
Start Indoors January 29 Jan 29 – Feb 12
Transplant Outdoors February 26 Feb 26 – Mar 12
Direct Sow February 5 Feb 5 – Feb 26
Harvest April 23 Apr 23 – Jun 18
Fall Sowing October 1 Oct 1 – Oct 15

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

50–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 9b

📆 Growing Season

273 days in Napa County

Growing Tips for Snow Peas in Napa County

Direct sow Snow Peas outdoors after February 26 in Napa County when soil has warmed and frost danger has passed.

Common pests for Snow Peas in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in early spring. Pick pods frequently when they are flat and tender for best flavor. Provide support for climbing varieties.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Snow Peas in Napa County, CA?

Napa County is in Zone 9b with an average last frost of February 26. Plan your Snow Peas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Napa County, CA?

Napa County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 26 and first fall frost is November 26.

🌱

Your Napa County Garden Planner — Free

A 24-page printable planner built for Napa County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Napa County, CA. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.