When to Plant Shiso in Humphreys County, TN
What to do in May
Your garden in Humphreys County, Tennessee is working on a schedule, even when you're not. Here's where you should be this May.
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Get shiso seeds going inside
Your window is short. These crops want several weeks of indoor growth before they go outside.
June prep starts now
- 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.
Humphreys County, Tennessee is in USDA Zone 7b. The average last spring frost is April 5 and the first fall frost is October 29, giving you a growing season of approximately 207 days.
At an elevation of 2,413 feet, Humphreys County receives approximately 49.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Shiso during the growing season.
Humphreys County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.5
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 Humphreys County
How your county's soil matches Shiso's growing requirements.
Soil pH
Your soil pH (5.8–6.5) is within Shiso's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in Humphreys County is excellent for Shiso — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Shiso.
How to Plant Shiso
Succession Planting Shiso
Sow every 5.7 weeks. Last sowing by Aug 20 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 | — | 4.9" | 0" | ❄️ Dormant |
| Feb | — | 3.5" | 0" | ❄️ Dormant |
| Mar | — | 5.2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| May | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Jun | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Jul | 4.3" | 5.6" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Oct | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Nov | — | 3.3" | 0" | ❄️ Dormant |
| Dec | — | 3.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Humphreys 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 — Humphreys County, TN
Shiso Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 15 | Feb 15 – Mar 1 |
| Transplant Outdoors | April 19 | Apr 19 – May 3 |
| Direct Sow | April 12 | Apr 12 – May 3 |
| Harvest | June 14 | Jun 14 – Aug 9 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| 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 · Only during dry spells
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: ideal
🗺️ USDA Zone
Zone 7b
📆 Growing Season
207 days in Humphreys County
Growing Tips for Shiso in Humphreys County
Direct sow Shiso outdoors after April 05 in Humphreys 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 Humphreys County, TN?
Humphreys County is in Zone 7b with an average last frost of April 5. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.
What planting zone is Humphreys County, TN?
Humphreys County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 5 and first fall frost is October 29.
Your Humphreys County Garden Planner — Free
A 24-page printable planner built for Humphreys 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.