When to Plant Yam in Tehama County, CA
May to-do list for Tehama County, California
Each item below is timed to Tehama County, California's frost dates and soil temperatures. Skip nothing, stress about nothing.
True yams are tropical tubers distinct from sweet potatoes, producing large starchy roots that can weigh several pounds. They are a staple food in tropical regions worldwide.
Tehama County, California is in USDA Zone 9b. The average last spring frost is March 6 and the first fall frost is November 28, giving you a growing season of approximately 267 days.
At an elevation of 78 feet, Tehama County receives approximately 44 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Yam to ensure they mature before fall.
Tehama County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.6
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 Tehama County
How your county's soil matches Yam's growing requirements.
Soil pH
Your soil pH (6.8–7.6) is more alkaline than Yam prefers (5.5–6.5). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Tehama County is excellent for Yam — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Yam.
How to Plant Yam
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Yam
Yam needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Yam Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 10.2" | 0" | ❄️ Dormant |
| Feb | — | 8.5" | 0" | ❄️ Dormant |
| Mar | 4.3" | 7" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| May | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Jun | 4.3" | 0.2" | 4.1" | 🚿 Regular watering |
| Jul | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Aug | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Sep | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Oct | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Nov | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Dec | — | 6.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Tehama County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Yam 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.
Yam Planting Timeline — Tehama County, CA
Yam Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 23 | Jan 23 – Feb 6 |
| Transplant Outdoors | March 13 | Mar 13 – Mar 27 |
| Direct Sow | March 6 | Mar 6 – Mar 27 |
| Harvest | September 11 | Sep 11 – Jan 8 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Harvest |
| February | Start Indoors |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | — |
| June | — |
| July | — |
| August | — |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | Harvest |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
180–330 days
🧪 Soil pH
Needs 5.5–6.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9b
📆 Growing Season
267 days in Tehama County
Growing Tips for Yam in Tehama County
Direct sow Yam outdoors after March 06 in Tehama County when soil has warmed and frost danger has passed.
Your 267.0-day growing season in Tehama County is tight for Yam (180.0-330.0 days to maturity). Start indoors and choose early-maturing varieties.
General growing tips
Plant tuber pieces in mounds of loose, rich soil. Provide sturdy trellising for climbing vines. Yams require a long, warm growing season of 8-11 months. Harvest when vines die back.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Yam in Other Locations
Frequently Asked Questions
When should I plant Yam in Tehama County, CA?
Tehama County is in Zone 9b with an average last frost of March 6. Plan your Yam planting based on this frost date — see the calendar above for exact timing.
What planting zone is Tehama County, CA?
Tehama County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 6 and first fall frost is November 28.
Your Tehama County Garden Planner — Free
A 24-page printable planner built for Tehama County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.