When to Plant Celtuce in San Bernardino County, CA
Your May planting checklist for San Bernardino County, California
Each item below is timed to San Bernardino County, California's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Basket week: celtuce
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
A few tasks this May that'll pay off in June
- First harvests: celtuce
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.
San Bernardino County, California is in USDA Zone 10a. The average last spring frost is February 24 and the first fall frost is November 25, giving you a growing season of approximately 274 days.
At an elevation of 1,012 feet, San Bernardino County receives approximately 16.9 inches of rainfall annually with predominantly loam soil. Summer highs average 97°F, so Celtuce may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Celtuce successfully. Mulch heavily to conserve soil moisture.
San Bernardino County Soil Profile
Soil Type
Loam
Soil pH
5.9-7.2
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 San Bernardino County
How your county's soil matches Celtuce's growing requirements.
Soil pH
Your soil pH (5.9–7.2) overlaps with Celtuce's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in San Bernardino County is excellent for Celtuce — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). 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 27 to harvest before frost.
For a dedicated fall crop, sow by Sep 30.
Plant Water Budget
Water stress score is 10/10 — 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 | — | 3.2" | 0" | ❄️ Dormant |
| Feb | 3" | 3.8" | 0" | ✅ Rainfall sufficient |
| Mar | 3" | 2.2" | 0.8" | 💧 Light watering |
| Apr | 3" | 1.5" | 1.5" | 🚿 Regular watering |
| May | 3" | 0.5" | 2.5" | 🚿 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" | 1.7" | 1.3" | 💧 Light watering |
| Dec | — | 3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in San Bernardino 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 — San Bernardino County, CA
Celtuce Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 27 | Jan 27 – Feb 10 |
| Transplant Outdoors | February 24 | Feb 24 – Mar 10 |
| Direct Sow | February 3 | Feb 3 – Feb 24 |
| Harvest | April 28 | Apr 28 – Jun 9 |
| Fall Sowing | September 30 | Sep 30 – Oct 14 |
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 | Fall Sowing |
| 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: acceptable
🗺️ USDA Zone
Zone 10a
📆 Growing Season
274 days in San Bernardino County
Growing Tips for Celtuce in San Bernardino County
Direct sow Celtuce outdoors after February 24 in San Bernardino County when soil has warmed and frost danger has passed.
With summer highs reaching 97°F in San Bernardino County, provide afternoon shade for Celtuce and water deeply in the morning.
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 San Bernardino County, CA?
San Bernardino County is in Zone 10a with an average last frost of February 24. Plan your Celtuce planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Bernardino County, CA?
San Bernardino County, California is in USDA Hardiness Zone 10a. The average last spring frost is February 24 and first fall frost is November 25.
Your San Bernardino County Garden Planner — Free
A 24-page printable planner built for San Bernardino 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.