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When to Plant Shiso in Webster County, MS

Webster County, Mississippi Zone 8a May

What to do in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Webster County, Mississippi.

Avg. last frost March 23
Avg. first frost November 7
Soil temp (4") 67°F
Watering Low
Pest pressure Moderate
Daylight 13.7 hrs
  1. Start shiso indoors

    Your window is short. These crops want several weeks of indoor growth before they go outside.

June will be here before you know it — start on
  • 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.

Webster County, Mississippi is in USDA Zone 8a. The average last spring frost is March 23 and the first fall frost is November 7, giving you a growing season of approximately 229 days.

At an elevation of 135 feet, Webster County receives approximately 56.5 inches of rainfall annually with predominantly clay loam soil. Summer highs average 93°F, providing good warmth for Shiso during the growing season. Clay soil retains moisture well for Shiso, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Shiso root diseases.

Webster County, MS (Zone 8a) Long season
229 days
Last Spring Frost March 23
229 growing days
First Fall Frost November 7
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Webster County Soil Profile

Soil Type

Clay Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (104 days to spare)
Start indoors: Jan 25 Transplant: Mar 29 🍅 Harvest: May 24 – Jul 19
Recommended (50%) ✓ Fits season (103 days to spare)
Start indoors: Feb 2 Transplant: Apr 6 🍅 Harvest: Jun 1 – Jul 27
Safe Start (90%) ✓ Fits season (102 days to spare)
Start indoors: Feb 22 Transplant: Apr 26 🍅 Harvest: Jun 21 – Aug 16

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 Webster County

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

Soil pH

Your soil pH (5.6–6.2) is within Shiso's preferred range (5.5–7.0).

Soil Texture

The clay loam soil in Webster 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

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

Succession Planting Shiso

5
successive plantings in your 229-day season

Sow every 5.7 weeks. Last sowing by Aug 29 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 5.1" 0" ❄️ Dormant
Feb 4.2" 0" ❄️ Dormant
Mar 4.3" 5.5" 0" ✅ Rainfall sufficient
Apr 4.3" 3.9" 0.4" 💧 Light watering
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.9" 0" ✅ Rainfall sufficient
Jul 4.3" 5.4" 0" ✅ Rainfall sufficient
Aug 4.3" 6.2" 0" ✅ Rainfall sufficient
Sep 4.3" 4.6" 0" ✅ Rainfall sufficient
Oct 4.3" 3.9" 0.4" 💧 Light watering
Nov 4.3" 4.6" 0" ✅ Rainfall sufficient
Dec 4.1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Webster 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 4,522 GDD Excellent fit

Shiso Planting Timeline — Webster County, MS

Shiso Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors April 6 Apr 6 – Apr 20
Direct Sow March 30 Mar 30 – Apr 20
Harvest June 1 Jun 1 – Jul 27

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Direct Sow
April Transplant Outdoors Direct Sow
May
June Harvest
July Harvest
August
September
October
November
December
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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 8a

📆 Growing Season

229 days in Webster County

Growing Tips for Shiso in Webster County

Direct sow Shiso outdoors after March 23 in Webster County when soil has warmed and frost danger has passed.

With Webster County's clay soil (28% clay), work in 3-4 inches of compost before planting Shiso. Avoid tilling when soil is wet to prevent compaction.

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 Webster County, MS?

Webster County is in Zone 8a with an average last frost of March 23. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Webster County, MS?

Webster County, Mississippi is in USDA Hardiness Zone 8a. The average last spring frost is March 23 and first fall frost is November 7.

🌱

Your Webster County Garden Planner — Free

A 24-page printable planner built for Webster County (Zone 8a). 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 Webster County, MS. 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.