Blog

When to Plant Celtuce in Marin County, CA

Celtuce (stem lettuce) is a Chinese vegetable grown for its thick, crunchy stem rather than its leaves. The peeled stem has a mild, cucumber-like flavor.

Marin County, California is in USDA Zone 10a. The average last spring frost is February 26 and the first fall frost is November 26, giving you a growing season of approximately 273 days.

At an elevation of 302 feet, Marin County receives approximately 36 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Celtuce to ensure they mature before fall. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Celtuce will need more frequent watering and organic matter to retain nutrients.

Marin County, CA (Zone 10a) Year-round
273 days
Last Spring Frost February 26
273 growing days
First Fall Frost November 26

Marin County Soil Profile

Soil Type

Sandy Loam

Soil pH

6-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (180 days to spare)
Start indoors: Jan 13 Transplant: Feb 10 🍅 Harvest: Apr 14 – May 26
Recommended (50%) ✓ Fits season (168 days to spare)
Start indoors: Jan 29 Transplant: Feb 26 🍅 Harvest: Apr 30 – Jun 11
Safe Start (90%) ✓ Fits season (154 days to spare)
Start indoors: Mar 5 Transplant: Apr 2 🍅 Harvest: Jun 4 – Jul 16

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 Marin County

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

Soil pH

Your soil pH (6.0โ€“6.9) is within Celtuce's preferred range (6.0โ€“7.0).

Soil Texture

Sandy soil in Marin County warms quickly in spring but drains fast. Celtuce will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Celtuce.

How to Plant Celtuce

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 Celtuce

5
successive plantings in your 273-day season

Sow every 6.9 weeks. Last sowing by Aug 28 to harvest before frost.

For a dedicated fall crop, sow by Oct 01.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.6″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 434 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Celtuce

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

Month Celtuce Needs Rainfall You Supplement Action
Jan โ€” 7.2" 0" โ„๏ธ Dormant
Feb 3" 6.5" 0" โœ… Rainfall sufficient
Mar 3" 6.2" 0" โœ… Rainfall sufficient
Apr 3" 2.7" 0.3" ๐Ÿ’ง Light watering
May 3" 1" 2" ๐Ÿšฟ Regular watering
Jun 3" 0.2" 2.8" ๐Ÿšฟ Regular watering
Jul 3" 0" 3" ๐Ÿšฟ Regular watering
Aug 3" 0" 3" ๐Ÿšฟ Regular watering
Sep 3" 0.4" 2.6" ๐Ÿšฟ Regular watering
Oct 3" 1.4" 1.6" ๐Ÿšฟ Regular watering
Nov 3" 3.5" 0" โœ… Rainfall sufficient
Dec โ€” 6.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Febโ€“Nov in Marin County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Celtuce 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" โ€” every day above 50ยฐF 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.

Celtuce needs ~806 GDD — county provides 2,945 GDD Excellent fit

Celtuce Planting Timeline โ€” Marin County, CA

Celtuce Planting Calendar

Activity When Date Range
Start Indoors January 29 Jan 29 โ€“ Feb 12
Transplant Outdoors February 26 Feb 26 โ€“ Mar 12
Direct Sow February 5 Feb 5 โ€“ Feb 26
Harvest April 30 Apr 30 โ€“ Jun 11
Fall Sowing October 1 Oct 1 โ€“ Oct 15

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.7"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 10a

๐Ÿ“† Growing Season

273 days in Marin County

Growing Tips for Celtuce in Marin County

Direct sow Celtuce outdoors after February 26 in Marin County when soil has warmed and frost danger has passed.

Sandy soil in Marin County dries quickly โ€” mulch Celtuce with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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

General growing tips

Direct sow in spring or start indoors. Space 12 inches apart. Harvest when stems are about 1 inch in diameter. Peel the tough outer skin to reveal the tender center.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Celtuce in Marin County, CA?

Marin County is in Zone 10a with an average last frost of February 26. Plan your Celtuce planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Marin County, CA?

Marin County, California is in USDA Hardiness Zone 10a. The average last spring frost is February 26 and first fall frost is November 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Marin County gardeners in Zone 10a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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