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When to Plant Lentils in Alameda County, CA

Alameda County, California Zone 10a May

Your May game plan for Alameda County, California

A quick May briefing for Alameda County, California gardeners — what's urgent, what's next, and what can wait.

Avg. last frost January 18
Avg. first frost December 12
Soil temp (4") 76°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. Pick lentils

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

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Lentils are an ancient pulse crop producing small, lens-shaped seeds packed with protein and iron. They grow on short, bushy plants and are surprisingly easy to cultivate.

Alameda 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 379 feet, Alameda County receives approximately 16.4 inches of rainfall annually with predominantly loam soil. Summer highs average 97°F, so Lentils may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Lentils successfully. Mulch heavily to conserve soil moisture.

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

Soil Type

Loam

Soil pH

6.3-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (199 days to spare)
Start indoors: Dec 17 Transplant: Jan 14 🍅 Harvest: Apr 8 – May 20
Recommended (50%) ✓ Fits season (202 days to spare)
Start indoors: Dec 21 Transplant: Jan 18 🍅 Harvest: Apr 12 – May 24
Safe Start (90%) ✓ Fits season (149 days to spare)
Start indoors: Feb 24 Transplant: Mar 24 🍅 Harvest: Jun 16 – 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 Alameda County

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

Soil pH

Your soil pH (6.3–7.7) is within Lentils's preferred range (6.0–8.0).

Soil Texture

The loam soil in Alameda County is excellent for Lentils — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Lentils

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Succession Planting Lentils

4
successive plantings in your 328-day season

Sow every 9.1 weeks. Last sowing by Aug 24 to harvest before frost.

For a dedicated fall crop, sow by Oct 17.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.2″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,373 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Lentils

Lentils needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Lentils Needs Rainfall You Supplement Action
Jan 2.6" 3" 0" ✅ Rainfall sufficient
Feb 2.6" 3.6" 0" ✅ Rainfall sufficient
Mar 2.6" 2.6" 0" ✅ Rainfall sufficient
Apr 2.6" 1.2" 1.4" 🚿 Regular watering
May 2.6" 0.4" 2.2" 🚿 Regular watering
Jun 2.6" 0.1" 2.5" 🚿 Regular watering
Jul 2.6" 0" 2.6" 🚿 Regular watering
Aug 2.6" 0" 2.6" 🚿 Regular watering
Sep 2.6" 0.2" 2.4" 🚿 Regular watering
Oct 2.6" 0.6" 2" 🚿 Regular watering
Nov 2.6" 1.5" 1.1" 💧 Light watering
Dec 2.6" 3.1" 0" ✅ Rainfall sufficient

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

Lentils 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.

Lentils needs ~2,161 GDD — county provides 7,484 GDD Excellent fit

Lentils Planting Timeline — Alameda County, CA

Lentils Planting Calendar

Activity When Date Range
Start Indoors December 21 Dec 21 – Jan 4
Transplant Outdoors January 18 Jan 18 – Feb 1
Direct Sow December 28 Dec 28 – Jan 18
Harvest April 12 Apr 12 – May 24
Fall Sowing October 17 Oct 17 – Oct 31

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.6"/week · 1-2 times/week

📅 Days to Maturity

80–110 days

🧪 Soil pH

Needs 6–8 · Your soil: ideal

🗺️ USDA Zone

Zone 10a

📆 Growing Season

328 days in Alameda County

Growing Tips for Lentils in Alameda County

Direct sow Lentils outdoors after January 18 in Alameda County when soil has warmed and frost danger has passed.

With summer highs reaching 97°F in Alameda County, provide afternoon shade for Lentils and water deeply in the morning.

Common pests for Lentils 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 as lentils tolerate frost. Provide short supports as plants tend to lodge. Harvest when lower pods turn brown. Pull entire plants and dry in bundles.

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 Lentils in Alameda County, CA?

Alameda County is in Zone 10a with an average last frost of January 18. Plan your Lentils planting based on this frost date — see the calendar above for exact timing.

What planting zone is Alameda County, CA?

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

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Your Alameda County Garden Planner — Free

A 24-page printable planner built for Alameda 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 Alameda 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.