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When to Plant Shiso in Limestone County, AL

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.

Limestone County, Alabama is in USDA Zone 7a. 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 200 feet, Limestone County receives approximately 54.7 inches of rainfall annually with predominantly clay loam soil. Summer highs average 93ยฐF, 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.

Limestone County, AL (Zone 7a) Long season
207 days
Last Spring Frost April 5
207 growing days
First Fall Frost October 29

Limestone County Soil Profile

Soil Type

Clay Loam

Soil pH

5.5-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (86 days to spare)
Start indoors: Feb 2 Transplant: Apr 6 🍅 Harvest: Jun 1 – Jul 27
Recommended (50%) ✓ Fits season (81 days to spare)
Start indoors: Feb 15 Transplant: Apr 19 🍅 Harvest: Jun 14 – Aug 9
Safe Start (90%) ✓ Fits season (84 days to spare)
Start indoors: Mar 5 Transplant: May 7 🍅 Harvest: Jul 2 – Aug 27

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 Limestone County

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

Soil pH

Your soil pH (5.5โ€“6.8) is within Shiso's preferred range (5.5โ€“7.0).

Soil Texture

The clay loam soil in Limestone County is excellent for Shiso โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). 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 207-day season

Sow every 5.7 weeks. Last sowing by Aug 20 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€” 4.4" 0" โ„๏ธ Dormant
Feb โ€” 4.6" 0" โ„๏ธ Dormant
Mar โ€” 5.4" 0" โ„๏ธ Dormant
Apr 4.3" 4.3" 0" โœ… Rainfall sufficient
May 4.3" 4.6" 0" โœ… Rainfall sufficient
Jun 4.3" 5.2" 0" โœ… Rainfall sufficient
Jul 4.3" 5.8" 0" โœ… Rainfall sufficient
Aug 4.3" 5.4" 0" โœ… Rainfall sufficient
Sep 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Oct 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Nov โ€” 4.5" 0" โ„๏ธ Dormant
Dec โ€” 3.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Limestone 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 ~1,185 GDD — county provides 4,088 GDD Excellent fit

Shiso Planting Timeline โ€” Limestone County, AL

Shiso Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 โ€“ Mar 1
Transplant Outdoors April 19 Apr 19 โ€“ May 3
Direct Sow April 12 Apr 12 โ€“ May 3
Harvest June 14 Jun 14 โ€“ Aug 9

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
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: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

207 days in Limestone County

Growing Tips for Shiso in Limestone County

Direct sow Shiso outdoors after April 05 in Limestone County when soil has warmed and frost danger has passed.

With Limestone 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 Limestone County, AL?

Limestone County is in Zone 7a with an average last frost of April 5. Plan your Shiso planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Limestone County, AL?

Limestone County, Alabama is in USDA Hardiness Zone 7a. The average last spring frost is April 5 and first fall frost is October 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Limestone County gardeners in Zone 7a 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 Limestone County, AL. Local conditions may vary. Last updated: April 2026.