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When to Plant Fava Beans in Santa Clara County, CA

Santa Clara County, California Zone 9b May

Your May planting checklist for Santa Clara County, California

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost February 19
Avg. first frost December 3
Soil temp (4") 74°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. Start harvesting fava beans

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Coming up in June — start thinking about
  • First harvests: fava beans

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Fava beans are a cool-season legume with large, meaty beans inside thick pods. They fix nitrogen in the soil and are one of the oldest cultivated crops.

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 Fava Beans during the growing season. With low rainfall, drip irrigation is essential for growing Fava Beans 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
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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)
Start indoors: Jan 4 Transplant: Feb 1 🍅 Harvest: Apr 19 – May 31
Recommended (50%) ✓ Fits season (168 days to spare)
Start indoors: Jan 22 Transplant: Feb 19 🍅 Harvest: May 7 – Jun 18
Safe Start (90%) ✓ Fits season (121 days to spare)
Start indoors: Mar 27 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 Fava Beans's growing requirements.

Soil pH

Your soil pH (6.7–7.8) is more alkaline than Fava Beans 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 Fava Beans — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Fava Beans

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

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

Succession Planting Fava Beans

4
successive plantings in your 287-day season

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

For a dedicated fall crop, sow by Oct 08.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.2″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 2,381 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Fava Beans

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

Month Fava Beans Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 4.3" 3.6" 0.7" 💧 Light watering
Mar 4.3" 2.6" 1.7" 💧 Light watering
Apr 4.3" 1.1" 3.2" 🚿 Regular watering
May 4.3" 0.3" 4" 🚿 Regular watering
Jun 4.3" 0.1" 4.2" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.1" 4.2" 🚿 Regular watering
Oct 4.3" 0.6" 3.7" 🚿 Regular watering
Nov 4.3" 1.4" 2.9" 🚿 Regular watering
Dec 4.3" 2.6" 1.7" 💧 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.

Fava Beans 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.

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

Fava Beans Planting Timeline — Santa Clara County, CA

Fava Beans Planting Calendar

Activity When Date Range
Start Indoors January 22 Jan 22 – Feb 5
Transplant Outdoors February 19 Feb 19 – Mar 5
Direct Sow January 29 Jan 29 – Feb 19
Harvest May 7 May 7 – Jun 18
Fall Sowing October 8 Oct 8 – Oct 22

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/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 Fava Beans in Santa Clara County

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

Common pests for Fava Beans 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. Fava Beans needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow as early as soil can be worked in spring. Pinch growing tips when pods begin to form to redirect energy and reduce aphid problems. Stake tall 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 Fava Beans in Santa Clara County, CA?

Santa Clara County is in Zone 9b with an average last frost of February 19. Plan your Fava Beans 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.