When to Plant Shiso in Gibson County, TN
May in Gibson County, Tennessee — your action list
Here's what deserves your attention in Gibson County, Tennessee this month. Everything below is tailored to Zone 7b and timed around your local frost dates.
-
Sow shiso in trays indoors
You're about 25 weeks out from your last frost — the perfect window to get these germinating indoors.
A few tasks this May that'll pay off in June
- First harvests: shiso
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.
Gibson County, Tennessee is in USDA Zone 7b. The average last spring frost is April 4 and the first fall frost is October 27, giving you a growing season of approximately 206 days.
At an elevation of 3,658 feet, Gibson County receives approximately 52.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Shiso during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Shiso root diseases.
Gibson County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.7
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 Gibson County
How your county's soil matches Shiso's growing requirements.
Soil pH
Your soil pH (5.5–6.7) is within Shiso's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in Gibson County is excellent for Shiso — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.8%). Annual compost additions will help Shiso.
How to Plant Shiso
Succession Planting Shiso
Sow every 5.7 weeks. Last sowing by Aug 18 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 | — | 4.5" | 0" | ❄️ Dormant |
| Feb | — | 4.9" | 0" | ❄️ Dormant |
| Mar | — | 5" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| May | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Jun | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 5.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5.2" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Oct | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Nov | — | 4.6" | 0" | ❄️ Dormant |
| Dec | — | 4.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Gibson 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 — Gibson County, TN
Shiso Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 14 | Feb 14 – Feb 28 |
| Transplant Outdoors | April 18 | Apr 18 – May 2 |
| Direct Sow | April 11 | Apr 11 – May 2 |
| Harvest | June 13 | Jun 13 – Aug 8 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors 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
1"/week · Natural rainfall sufficient
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: ideal
🗺️ USDA Zone
Zone 7b
📆 Growing Season
206 days in Gibson County
Growing Tips for Shiso in Gibson County
Direct sow Shiso outdoors after April 04 in Gibson County when soil has warmed and frost danger has passed.
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 Gibson County, TN?
Gibson County is in Zone 7b with an average last frost of April 4. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.
What planting zone is Gibson County, TN?
Gibson County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 4 and first fall frost is October 27.
Your Gibson County Garden Planner — Free
A 24-page printable planner built for Gibson County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.