When to Plant Celtuce in Contra Costa 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.
Contra Costa County, California is in USDA Zone 9b. The average last spring frost is February 26 and the first fall frost is November 29, giving you a growing season of approximately 276 days.
At an elevation of 88 feet, Contra Costa County receives approximately 19 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Celtuce during the growing season. With low rainfall, drip irrigation is essential for growing Celtuce successfully. Mulch heavily to conserve soil moisture.
Contra Costa County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.8
Drainage
Well Drained
Plant Planting Risk Windows
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 Contra Costa County
How your county's soil matches Celtuce's growing requirements.
Soil pH
Your soil pH (6.7–7.8) is more alkaline than Celtuce prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Contra Costa County is excellent for Celtuce — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). Annual compost additions will help Celtuce.
How to Plant Celtuce
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Celtuce
Sow every 6.9 weeks. Last sowing by Aug 31 to harvest before frost.
For a dedicated fall crop, sow by Oct 04.
Plant Water Budget
Water stress score is 8/10 — 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 | — | 4.1" | 0" | ❄️ Dormant |
| Feb | 3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Mar | 3" | 3" | 0" | ✅ Rainfall sufficient |
| Apr | 3" | 1.5" | 1.5" | 🚿 Regular watering |
| May | 3" | 0.6" | 2.4" | 🚿 Regular watering |
| Jun | 3" | 0.1" | 2.9" | 🚿 Regular watering |
| Jul | 3" | 0" | 3" | 🚿 Regular watering |
| Aug | 3" | 0" | 3" | 🚿 Regular watering |
| Sep | 3" | 0.2" | 2.8" | 🚿 Regular watering |
| Oct | 3" | 0.7" | 2.3" | 🚿 Regular watering |
| Nov | 3" | 1.6" | 1.4" | 💧 Light watering |
| Dec | — | 2.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in Contra Costa 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 Planting Timeline — Contra Costa County, CA
Celtuce Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 29 | Jan 29 – Feb 12 |
| Transplant Outdoors | February 26 | Feb 26 – Mar 12 |
| Direct Sow | February 5 | Feb 5 – Feb 26 |
| Harvest | April 30 | Apr 30 – Jun 11 |
| Fall Sowing | October 4 | Oct 4 – Oct 18 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Transplant Outdoors |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.7"/week · 1-2 times/week
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9b
📆 Growing Season
276 days in Contra Costa County
Growing Tips for Celtuce in Contra Costa County
Direct sow Celtuce outdoors after February 26 in Contra Costa County when soil has warmed and frost danger has passed.
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 →
Celtuce in Other Locations
Frequently Asked Questions
When should I plant Celtuce in Contra Costa County, CA?
Contra Costa County is in Zone 9b with an average last frost of February 26. Plan your Celtuce planting based on this frost date — see the calendar above for exact timing.
What planting zone is Contra Costa County, CA?
Contra Costa County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 26 and first fall frost is November 29.
Plan Your Garden with Confidence
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