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When to Plant Edamame in Santa Clara County, CA

Santa Clara County, California Zone 9b May

May in Santa Clara County, California — your action list

Here's what deserves your attention in Santa Clara County, California this month. Everything below is tailored to Zone 9b and timed around your local frost dates.

Avg. last frost February 19
Avg. first frost December 3
Soil temp (4") 74°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. Collect edamame at their peak

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Get ahead of June
  • First harvests: edamame

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Edamame are soybeans harvested at the immature green stage for a sweet, nutty snack. They are high in protein and easy to grow in warm climates.

Santa Clara County, California is in USDA Zone 9b. The average last spring frost is February 19 and the first fall frost is December 3, giving you a growing season of approximately 287 days.

At an elevation of 455 feet, Santa Clara County receives approximately 15.5 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Edamame during the growing season. With low rainfall, drip irrigation is essential for growing Edamame successfully. Mulch heavily to conserve soil moisture.

Santa Clara County, CA (Zone 9b) Year-round
287 days
Last Spring Frost February 19
287 growing days
First Fall Frost December 3

Santa Clara County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (176 days to spare)
Transplant: Feb 1 🍅 Harvest: Apr 19 – May 31
Recommended (50%) ✓ Fits season (168 days to spare)
Transplant: Feb 19 🍅 Harvest: May 7 – Jun 18
Safe Start (90%) ✓ Fits season (121 days to spare)
Transplant: Apr 24 🍅 Harvest: Jul 10 – Aug 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.

Soil Compatibility in Santa Clara County

How your county's soil matches Edamame's growing requirements.

Soil pH

Your soil pH (6.7–7.8) is more alkaline than Edamame prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Santa Clara County is excellent for Edamame — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Edamame.

How to Plant Edamame

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Edamame

4
successive plantings in your 287-day season

Sow every 8.6 weeks. Last sowing by Aug 25 to harvest before frost.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.2″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 2,073 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Edamame

Edamame needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Edamame Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 3.9" 3.6" 0.3" 💧 Light watering
Mar 3.9" 2.6" 1.3" 💧 Light watering
Apr 3.9" 1.1" 2.8" 🚿 Regular watering
May 3.9" 0.3" 3.6" 🚿 Regular watering
Jun 3.9" 0.1" 3.8" 🚿 Regular watering
Jul 3.9" 0" 3.9" 🚿 Regular watering
Aug 3.9" 0" 3.9" 🚿 Regular watering
Sep 3.9" 0.1" 3.8" 🚿 Regular watering
Oct 3.9" 0.6" 3.3" 🚿 Regular watering
Nov 3.9" 1.4" 2.5" 🚿 Regular watering
Dec 3.9" 2.6" 1.3" 💧 Light watering

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

Edamame 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.

Edamame needs ~1,662 GDD — county provides 5,472 GDD Excellent fit

Edamame Planting Timeline — Santa Clara County, CA

Edamame Planting Calendar

Activity When Date Range
Direct Sow February 26 Feb 26 – Mar 19
Harvest May 14 May 14 – Jun 25

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Direct Sow
March Direct Sow
April
May Harvest
June Harvest
July
August
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · 2-3 times/week

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

287 days in Santa Clara County

Growing Tips for Edamame in Santa Clara County

Direct sow Edamame outdoors after February 19 in Santa Clara County when soil has warmed and frost danger has passed.

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

Santa Clara County receives only 16" of rain annually. Edamame needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after soil is warm. Do not over-fertilize with nitrogen. Harvest when pods are plump and bright green but before they start to yellow. Steam or boil pods before eating.

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 Edamame in Santa Clara County, CA?

Santa Clara County is in Zone 9b with an average last frost of February 19. Plan your Edamame planting based on this frost date — see the calendar above for exact timing.

What planting zone is Santa Clara County, CA?

Santa Clara County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 19 and first fall frost is December 3.

🌱

Your Santa Clara County Garden Planner — Free

A 24-page printable planner built for Santa Clara 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 Santa Clara 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.