When to Plant Shiso in Jackson County, TX
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.
Jackson County, Texas is in USDA Zone 9a. The average last spring frost is February 21 and the first fall frost is December 5, giving you a growing season of approximately 287 days.
At an elevation of 286 feet, Jackson County receives approximately 64.3 inches of rainfall annually with predominantly loam soil. Summer highs average 103°F, so Shiso may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Shiso root diseases.
Jackson County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.2
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 Jackson County
How your county's soil matches Shiso's growing requirements.
Soil pH
Your soil pH (6.5–7.2) overlaps with Shiso's range (5.5–7.0), though not a perfect match.
Soil Texture
The loam soil in Jackson County is excellent for Shiso — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Shiso.
Organic Matter
Organic matter is moderate (2.0%). Annual compost additions will help Shiso.
How to Plant Shiso
Succession Planting Shiso
Sow every 5.7 weeks. Last sowing by Sep 26 to harvest before frost.
Plant Water Budget
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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Mar | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Apr | 4.3" | 6.5" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 9" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 10.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 7.9" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 8" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 6" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Nov | 4.3" | 2.3" | 2" | 💧 Light watering |
| Dec | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
Water needs are for active growing months only (Feb–Dec in Jackson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Shiso 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.
Shiso Planting Timeline — Jackson County, TX
Shiso Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 10 | Jan 10 – Jan 24 |
| Transplant Outdoors | February 28 | Feb 28 – Mar 14 |
| Direct Sow | February 28 | Feb 28 – Mar 21 |
| Harvest | April 25 | Apr 25 – Jun 20 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
287 days in Jackson County
Growing Tips for Shiso in Jackson County
Direct sow Shiso outdoors after February 21 in Jackson County when soil has warmed and frost danger has passed.
With summer highs reaching 103°F in Jackson County, provide afternoon shade for Shiso and water deeply in the morning.
General growing tips
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 Jackson County, TX?
Jackson County is in Zone 9a with an average last frost of February 21. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jackson County, TX?
Jackson County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 21 and first fall frost is December 5.
Plan Your Garden with Confidence
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