Blog

When to Plant Celtuce in Lake County, CA

Lake County, California Zone 9a May

May in the garden — Lake 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 March 2
Avg. first frost November 27
Soil temp (4") 71°F
Watering Critical
Pest pressure High
Daylight 14.1 hrs
  1. Basket week: celtuce

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

June prep starts now
  • First harvests: celtuce

Instant PDF download. No spam, unsubscribe any time.

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.

Lake County, California is in USDA Zone 9a. The average last spring frost is March 2 and the first fall frost is November 27, giving you a growing season of approximately 270 days.

At an elevation of 154 feet, Lake County receives approximately 30.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 83°F, so choose short-season varieties of Celtuce to ensure they mature before fall. Sandy soil warms quickly in spring — great for early planting — but Celtuce will need more frequent watering and organic matter to retain nutrients.

Lake County, CA (Zone 9a) Year-round
270 days
Last Spring Frost March 2
270 growing days
First Fall Frost November 27

Lake County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.1-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (173 days to spare)
Start indoors: Jan 17 Transplant: Feb 14 🍅 Harvest: Apr 18 – May 30
Recommended (50%) ✓ Fits season (165 days to spare)
Start indoors: Feb 2 Transplant: Mar 2 🍅 Harvest: May 4 – Jun 15
Safe Start (90%) ✓ Fits season (136 days to spare)
Start indoors: Mar 20 Transplant: Apr 17 🍅 Harvest: Jun 19 – Jul 31

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 Lake County

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

Soil pH

Your soil pH (6.1–6.9) is within Celtuce's preferred range (6.0–7.0).

Soil Texture

Sandy soil in Lake 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 (2.7%). 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 270-day season

Sow every 6.9 weeks. Last sowing by Aug 29 to harvest before frost.

For a dedicated fall crop, sow by Oct 02.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.5″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 546 gal / 100 sq ft

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 6.2" 0" ❄️ Dormant
Feb 6.5" 0" ❄️ Dormant
Mar 3" 4.6" 0" ✅ Rainfall sufficient
Apr 3" 2.7" 0.3" 💧 Light watering
May 3" 0.8" 2.2" 🚿 Regular watering
Jun 3" 0.2" 2.8" 🚿 Regular watering
Jul 3" 0" 3" 🚿 Regular watering
Aug 3" 0" 3" 🚿 Regular watering
Sep 3" 0.3" 2.7" 🚿 Regular watering
Oct 3" 1.1" 1.9" 🚿 Regular watering
Nov 3" 3" 0" ✅ Rainfall sufficient
Dec 5.1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Lake County). Supplement amounts are based on average rainfall — 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" — 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.

Celtuce needs ~919 GDD — county provides 3,307 GDD Excellent fit

Celtuce Planting Timeline — Lake County, CA

Celtuce Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors March 2 Mar 2 – Mar 16
Direct Sow February 9 Feb 9 – Mar 2
Harvest May 4 May 4 – Jun 15
Fall Sowing October 2 Oct 2 – Oct 16

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 9a

📆 Growing Season

270 days in Lake County

Growing Tips for Celtuce in Lake County

Direct sow Celtuce outdoors after March 02 in Lake County when soil has warmed and frost danger has passed.

Sandy soil in Lake County dries quickly — 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 Lake County, CA?

Lake County is in Zone 9a with an average last frost of March 2. Plan your Celtuce planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lake County, CA?

Lake County, California is in USDA Hardiness Zone 9a. The average last spring frost is March 2 and first fall frost is November 27.

🌱

Your Lake County Garden Planner — Free

A 24-page printable planner built for Lake County (Zone 9a). 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 Lake 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.