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When to Plant Shiso in Bibb 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.

Bibb County, Alabama is in USDA Zone 7b. The average last spring frost is March 14 and the first fall frost is November 13, giving you a growing season of approximately 244 days.

At an elevation of 66 feet, Bibb County receives approximately 59.2 inches of rainfall annually with predominantly clay loam soil. Summer highs average 92ยฐF, 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.

Bibb County, AL (Zone 7b) Long season
244 days
Last Spring Frost March 14
244 growing days
First Fall Frost November 13

Bibb County Soil Profile

Soil Type

Clay Loam

Soil pH

5.3-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (118 days to spare)
Start indoors: Jan 17 Transplant: Mar 21 🍅 Harvest: May 16 – Jul 11
Recommended (50%) ✓ Fits season (118 days to spare)
Start indoors: Jan 24 Transplant: Mar 28 🍅 Harvest: May 23 – Jul 18
Safe Start (90%) ✓ Fits season (115 days to spare)
Start indoors: Feb 13 Transplant: Apr 17 🍅 Harvest: Jun 12 – Aug 7

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 Bibb County

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

Soil pH

Your soil pH (5.3โ€“6.6) overlaps with Shiso's range (5.5โ€“7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Shiso.

Organic Matter

Organic matter is moderate (2.2%). 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 244-day season

Sow every 5.7 weeks. Last sowing by Sep 04 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 โ€” 4.6" 0" โ„๏ธ Dormant
Feb โ€” 4.2" 0" โ„๏ธ Dormant
Mar 4.3" 6.3" 0" โœ… Rainfall sufficient
Apr 4.3" 5.4" 0" โœ… Rainfall sufficient
May 4.3" 4.3" 0" โœ… Rainfall sufficient
Jun 4.3" 4.9" 0" โœ… Rainfall sufficient
Jul 4.3" 6" 0" โœ… Rainfall sufficient
Aug 4.3" 6.5" 0" โœ… Rainfall sufficient
Sep 4.3" 4.3" 0" โœ… Rainfall sufficient
Oct 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Nov 4.3" 4.8" 0" โœ… Rainfall sufficient
Dec โ€” 4.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Bibb 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 ~1,140 GDD — county provides 4,636 GDD Excellent fit

Shiso Planting Timeline โ€” Bibb County, AL

Shiso Planting Calendar

Activity When Date Range
Start Indoors January 24 Jan 24 โ€“ Feb 7
Transplant Outdoors March 28 Mar 28 โ€“ Apr 11
Direct Sow March 21 Mar 21 โ€“ Apr 11
Harvest May 23 May 23 โ€“ Jul 18

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

Month-by-Month Timeline

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

244 days in Bibb County

Growing Tips for Shiso in Bibb County

Direct sow Shiso outdoors after March 14 in Bibb County when soil has warmed and frost danger has passed.

With Bibb County's clay soil (26% 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 Bibb County, AL?

Bibb County is in Zone 7b with an average last frost of March 14. Plan your Shiso planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Bibb County, AL?

Bibb County, Alabama is in USDA Hardiness Zone 7b. The average last spring frost is March 14 and first fall frost is November 13.

๐ŸŒฑ

Plan Your Garden with Confidence

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

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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 Bibb County, AL. Local conditions may vary. Last updated: April 2026.