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When to Plant Christmas Lima Beans in San Mateo County, CA

San Mateo County, California Zone 10a May

Your May gardening checklist

Each item below is timed to San Mateo County, California's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost January 18
Avg. first frost December 12
Soil temp (4") 78°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. It's harvest week for christmas lima beans

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

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Christmas lima beans are a large, beautifully marbled heirloom bean with a rich, chestnut-like flavor. They are a climbing variety that produces generously in warm weather.

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 81°F, so choose short-season varieties of Christmas Lima Beans to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Christmas Lima Beans 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 (199 days to spare)
Start indoors: Dec 3 Transplant: Jan 21 🍅 Harvest: Apr 15 – May 20
Recommended (50%) ✓ Fits season (202 days to spare)
Start indoors: Dec 7 Transplant: Jan 25 🍅 Harvest: Apr 19 – May 24
Safe Start (90%) ✓ Fits season (149 days to spare)
Start indoors: Feb 10 Transplant: Mar 31 🍅 Harvest: Jun 23 – Jul 28

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 San Mateo County

How your county's soil matches Christmas Lima Beans's growing requirements.

Soil pH

Your soil pH (6.8–7.2) overlaps with Christmas Lima Beans's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in San Mateo County is excellent for Christmas Lima Beans — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Christmas Lima Beans.

Organic Matter

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

How to Plant Christmas Lima Beans

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

Succession Planting Christmas Lima Beans

4
successive plantings in your 328-day season

Sow every 9.1 weeks. Last sowing by Sep 03 to harvest before frost.

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 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Christmas Lima Beans

Christmas Lima 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 Christmas Lima Beans Needs Rainfall You Supplement Action
Jan 4.3" 3.9" 0.4" 💧 Light watering
Feb 4.3" 3.4" 0.9" 💧 Light watering
Mar 4.3" 2.7" 1.6" 💧 Light watering
Apr 4.3" 1.2" 3.1" 🚿 Regular watering
May 4.3" 0.4" 3.9" 🚿 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" 0.2" 4.1" 🚿 Regular watering
Oct 4.3" 0.7" 3.6" 🚿 Regular watering
Nov 4.3" 1.4" 2.9" 🚿 Regular watering
Dec 4.3" 2.9" 1.4" 💧 Light watering

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

Christmas Lima 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.

Christmas Lima Beans needs ~968 GDD — county provides 3,536 GDD Excellent fit

Christmas Lima Beans Planting Timeline — San Mateo County, CA

Christmas Lima Beans Planting Calendar

Activity When Date Range
Start Indoors December 7 Dec 7 – Dec 21
Transplant Outdoors January 25 Jan 25 – Feb 8
Direct Sow January 18 Jan 18 – Feb 8
Harvest April 19 Apr 19 – May 24

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

80–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 10a

📆 Growing Season

328 days in San Mateo County

Growing Tips for Christmas Lima Beans in San Mateo County

Direct sow Christmas Lima Beans outdoors after January 18 in San Mateo County when soil has warmed and frost danger has passed.

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

San Mateo County receives only 17" of rain annually. Christmas Lima Beans needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after soil is warm. Provide tall trellising for vigorous vines. Harvest for fresh shelling when pods are plump or allow to dry on the vine for storage.

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 Christmas Lima Beans in San Mateo County, CA?

San Mateo County is in Zone 10a with an average last frost of January 18. Plan your Christmas Lima Beans planting based on this frost date — 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.

🌱

Your San Mateo County Garden Planner — Free

A 24-page printable planner built for San Mateo County (Zone 10a). 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 San Mateo 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.