When to Plant Shiso in Trinity County, CA
Shiso (perilla) is a fragrant Japanese herb with large, ruffled leaves in green or purple varieties. It has a unique flavor combining mint, basil, and anise.
Trinity County, California is in USDA Zone 7b. The average last spring frost is April 19 and the first fall frost is October 25, giving you a growing season of approximately 189 days.
At an elevation of 61 feet, Trinity County receives approximately 30.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 79°F, so choose short-season varieties of Shiso to ensure they mature before fall. Sandy soil warms quickly in spring — great for early planting — but Shiso will need more frequent watering and organic matter to retain nutrients.
Trinity County Soil Profile
Soil Type
Sandy Loam
Soil pH
6-7.1
Drainage
Well Drained
Monthly Watering Guide for Shiso
Shiso needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Shiso Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 6.2" | 0" | ❄️ Dormant |
| Feb | — | 6.6" | 0" | ❄️ Dormant |
| Mar | — | 5" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| May | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Jun | 4.3" | 0.1" | 4.2" | 🚿 Regular watering |
| Jul | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Aug | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Sep | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Oct | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 4.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Trinity County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Shiso Planting Timeline — Trinity County, CA
Shiso Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 1 | Mar 1 – Mar 15 |
| Transplant Outdoors | May 3 | May 3 – May 17 |
| Direct Sow | April 26 | Apr 26 – May 17 |
| Harvest | June 28 | Jun 28 – Aug 23 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: N/A
🗺️ USDA Zone
Zone 7b
📆 Growing Season
189 days in Trinity County
Growing Tips for Trinity County
Direct sow after last frost or start indoors. Both green and red varieties are available. Pinch tips to encourage bushiness. Self-sows prolifically; deadhead to control.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Shiso in Other Locations
Frequently Asked Questions
When should I plant Shiso in Trinity County, CA?
Trinity County is in Zone 7b with an average last frost of April 19. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.
What planting zone is Trinity County, CA?
Trinity County, California is in USDA Hardiness Zone 7b. The average last spring frost is April 19 and first fall frost is October 25.
Plan Your Garden with Confidence
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