Blog

When to plant Lettuce in Modoc County, CA

Modoc County's climate puts the Lettuce spring window between May 17 and June 7. time plantings around the expected last-frost window for best survival. A second sowing from July 13 to July 27 extends the harvest into fall.

When to Plant Lettuce in Modoc County, CA

Lettuce
Modoc County, California Zone 6b July

This month in Modoc County, California

Here's what deserves your attention in Modoc County, California this month. Everything below is tailored to Zone 6b and timed around your local frost dates.

Avg. last frost May 31
Avg. first frost September 21
Soil temp (4") 78°F
Watering Critical
Pest pressure High
Daylight 14.7 hrs
  1. Get lettuce seeds going inside

    Your window is short. These crops want several weeks of indoor growth before they go outside.

  2. Collect lettuce at their peak

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

  3. Get lettuce in for a late-season harvest

    A row cover ready in the garage extends your harvest by weeks once the nights turn cold.

Before August arrives, get these ready
  • First harvests: lettuce

Instant PDF download. No spam, unsubscribe any time.

Lettuce is a fast-growing cool-season green available in leaf, romaine, butterhead, and crisphead types. It is the foundation of salads and one of the easiest crops to grow.

Modoc County, California is in USDA Zone 6b. The average last spring frost is May 31 and the first fall frost is September 21, giving you a growing season of approximately 113 days.

At an elevation of 2,205 feet, Modoc County receives approximately 28.3 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Lettuce to ensure they mature before fall.

Modoc County, CA (Zone 6b) Short season
113 days
Last Spring Frost May 31
113 growing days
First Fall Frost September 21

Modoc County Soil Profile

Soil Type

Loam

Soil pH

5.9-7.4

Drainage

Well Drained

Lettuce Planting Risk Windows

Early Start (70% safe) ✓ Fits season (15 days to spare)
Start indoors: Apr 14 Transplant: May 19 🍅 Harvest: Jun 23 – Sep 1
Recommended (50%) ✓ Fits season (8 days to spare)
Start indoors: Apr 26 Transplant: May 31 🍅 Harvest: Jul 5 – Sep 13
Safe Start (90%) ✓ Fits season (14 days to spare)
Start indoors: May 15 Transplant: Jun 19 🍅 Harvest: Jul 24 – Oct 2

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 Modoc County

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

Soil pH

Your soil pH (5.9–7.4) overlaps with Lettuce's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Lettuce.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Lettuce.

How to Plant Lettuce

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Lettuce

4
successive plantings in your 113-day season

Sow every 3.4 weeks. Last sowing by Jul 23 to harvest before frost.

For a dedicated fall crop, sow by Jul 13.

Lettuce Water Budget

Plant needs
0.7″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Lettuce

Lettuce needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Lettuce Needs Rainfall You Supplement Action
Jan 5.6" 0" ❄️ Dormant
Feb 5.8" 0" ❄️ Dormant
Mar 4.1" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 3" 0.7" 2.3" 🚿 Regular watering
Jun 3" 0.1" 2.9" 🚿 Regular watering
Jul 3" 0" 3" 🚿 Regular watering
Aug 3" 0" 3" 🚿 Regular watering
Sep 3" 0.4" 2.6" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 2.7" 0" ❄️ Dormant
Dec 5.5" 0" ❄️ Dormant

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

Lettuce 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.

Lettuce needs ~551 GDD — county provides 1,384 GDD Excellent fit

Lettuce Planting Timeline — Modoc County, CA

Lettuce Planting Calendar

Activity When Date Range
Start Indoors April 26 Apr 26 – May 10
Transplant Outdoors May 31 May 31 – Jun 14
Direct Sow May 17 May 17 – Jun 7
Harvest July 5 Jul 5 – Sep 13
Fall Sowing July 13 Jul 13 – Jul 27

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

30–60 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

113 days in Modoc County

Growing Tips for Lettuce in Modoc County

Direct sow Lettuce outdoors after May 31 in Modoc County when soil has warmed and frost danger has passed.

Common pests for Lettuce in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Sow seeds directly every 2 weeks for continuous harvest. Provide afternoon shade in warm weather to delay bolting. Harvest in the morning for crispest leaves.

Recommended Lettuce Varieties for Modoc County

Fast-maturing leaf and butterhead types

Salad Bowl (40d) Black Seeded Simpson (45d) Buttercrunch (50d)

Companion Planting

Good Companions

Avoid Planting Near

  • Celery

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Lettuce Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let plants bolt and flower. Harvest seed heads when fluffy.
Storage Store airtight; viable 6 years at 35°F, under 45% humidity.

Very easy to save. Let a few plants bolt each season.

Frequently Asked Questions

When should I plant Lettuce in Modoc County, CA?

Modoc County is in Zone 6b with an average last frost of May 31. Plan your Lettuce planting based on this frost date — see the calendar above for exact timing.

What planting zone is Modoc County, CA?

Modoc County, California is in USDA Hardiness Zone 6b. The average last spring frost is May 31 and first fall frost is September 21.

When should I plant Lettuce in Modoc County, CA?

In Modoc County, CA, plant Lettuce after the last frost (around May 31) and before the first frost (around September 21). Best results when soil holds above 50°F.

What growing zone is Modoc County, CA for Lettuce?

Modoc County sits in USDA Zone 6b. Lettuce grows reliably in zones 2a through 11b, so it's a good fit here.

Can Lettuce grow in Modoc County's climate?

Yes — Lettuce grows well in Modoc County's temperate climate. Modoc County averages a 113-day frost-free season, with last frost around May 31 and first frost around September 21.

🌱

Your Modoc County Garden Planner — Free

A 22-page printable planner built for Modoc County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Modoc County, CA. Local conditions may vary. Last updated: July 2026.

Sources & credits

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