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When to Plant Shiso in Trousdale County, TN

Trousdale County, Tennessee Zone 7b May

Your May planting checklist for Trousdale County, Tennessee

We've pulled the most time-sensitive tasks for Trousdale County, Tennessee this May and put them front and centre. Tackle them in order.

Avg. last frost April 9
Avg. first frost October 28
Soil temp (4") 59°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Get shiso seeds going inside

    These need a head start before your last frost (April 9). Sow into cells now so you're ready to transplant in a few weeks.

To set up a strong June, finish these tasks
  • First harvests: shiso

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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.

Trousdale County, Tennessee is in USDA Zone 7b. The average last spring frost is April 9 and the first fall frost is October 28, giving you a growing season of approximately 202 days.

At an elevation of 3,985 feet, Trousdale County receives approximately 42.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Shiso during the growing season.

Trousdale County, TN (Zone 7b) Long season
202 days
Last Spring Frost April 9
202 growing days
First Fall Frost October 28

Trousdale County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (75 days to spare)
Start indoors: Feb 14 Transplant: Apr 18 🍅 Harvest: Jun 13 – Aug 8
Recommended (50%) ✓ Fits season (76 days to spare)
Start indoors: Feb 19 Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 13
Safe Start (90%) ✓ Fits season (79 days to spare)
Start indoors: Mar 3 Transplant: May 5 🍅 Harvest: Jun 30 – Aug 25

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 Trousdale County

How your county's soil matches Shiso's growing requirements.

Soil pH

Your soil pH (5.6–6.7) is within Shiso's preferred range (5.5–7.0).

Soil Texture

The silt loam soil in Trousdale County is excellent for Shiso — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Shiso.

How to Plant Shiso

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Shiso

4
successive plantings in your 202-day season

Sow every 5.7 weeks. Last sowing by Aug 19 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 242 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 3.8" 0" ❄️ Dormant
Feb 3.5" 0" ❄️ Dormant
Mar 4.4" 0" ❄️ Dormant
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 3.8" 0.5" 💧 Light watering
Jul 4.3" 4.2" 0.1" 💧 Light watering
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3" 1.3" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Trousdale 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 needs ~1,185 GDD — county provides 3,989 GDD Excellent fit

Shiso Planting Timeline — Trousdale County, TN

Shiso Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 16 Apr 16 – May 7
Harvest June 18 Jun 18 – Aug 13

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
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

202 days in Trousdale County

Growing Tips for Shiso in Trousdale County

Direct sow Shiso outdoors after April 09 in Trousdale 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 →

Frequently Asked Questions

When should I plant Shiso in Trousdale County, TN?

Trousdale County is in Zone 7b with an average last frost of April 9. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Trousdale County, TN?

Trousdale County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 9 and first fall frost is October 28.

🌱

Your Trousdale County Garden Planner — Free

A 24-page printable planner built for Trousdale 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Trousdale County, TN. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.