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When to Plant Shiso in Dawson County, GA

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.

Dawson County, Georgia is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is November 3, giving you a growing season of approximately 217 days.

At an elevation of 433 feet, Dawson County receives approximately 54.8 inches of rainfall annually with predominantly clay loam soil. Summer highs average 94ยฐF, 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.

Dawson County, GA (Zone 7b) Long season
217 days
Last Spring Frost March 31
217 growing days
First Fall Frost November 3

Dawson County Soil Profile

Soil Type

Clay Loam

Soil pH

5.2-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (88 days to spare)
Start indoors: Feb 2 Transplant: Apr 6 🍅 Harvest: Jun 1 – Jul 27
Recommended (50%) ✓ Fits season (91 days to spare)
Start indoors: Feb 10 Transplant: Apr 14 🍅 Harvest: Jun 9 – Aug 4
Safe Start (90%) ✓ Fits season (86 days to spare)
Start indoors: Mar 7 Transplant: May 9 🍅 Harvest: Jul 4 – Aug 29

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 Dawson County

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

Soil pH

Your soil pH (5.2โ€“6.3) overlaps with Shiso's range (5.5โ€“7.0), though not a perfect match.

Soil Texture

The clay loam soil in Dawson County is excellent for Shiso โ€” 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 217-day season

Sow every 5.7 weeks. Last sowing by Aug 25 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/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 โ€” 3.8" 0" โ„๏ธ Dormant
Feb โ€” 4.5" 0" โ„๏ธ Dormant
Mar 4.3" 4.9" 0" โœ… Rainfall sufficient
Apr 4.3" 4.4" 0" โœ… Rainfall sufficient
May 4.3" 4.6" 0" โœ… Rainfall sufficient
Jun 4.3" 4.6" 0" โœ… Rainfall sufficient
Jul 4.3" 5.6" 0" โœ… Rainfall sufficient
Aug 4.3" 5.8" 0" โœ… Rainfall sufficient
Sep 4.3" 4.5" 0" โœ… Rainfall sufficient
Oct 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Nov 4.3" 4.6" 0" โœ… Rainfall sufficient
Dec โ€” 3.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Dawson County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,230 GDD — county provides 4,448 GDD Excellent fit

Shiso Planting Timeline โ€” Dawson County, GA

Shiso Planting Calendar

Activity When Date Range
Start Indoors February 10 Feb 10 โ€“ Feb 24
Transplant Outdoors April 14 Apr 14 โ€“ Apr 28
Direct Sow April 7 Apr 7 โ€“ Apr 28
Harvest June 9 Jun 9 โ€“ Aug 4

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

50โ€“70 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

217 days in Dawson County

Growing Tips for Shiso in Dawson County

Direct sow Shiso outdoors after March 31 in Dawson County when soil has warmed and frost danger has passed.

With Dawson County's clay soil (32% 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 Dawson County, GA?

Dawson County is in Zone 7b with an average last frost of March 31. Plan your Shiso planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Dawson County, GA?

Dawson County, Georgia is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is November 3.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Dawson County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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