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When to Plant Shiso in Concho County, TX

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.

Concho County, Texas is in USDA Zone 8a. The average last spring frost is March 25 and the first fall frost is November 12, giving you a growing season of approximately 232 days.

At an elevation of 3,848 feet, Concho County receives approximately 58.2 inches of rainfall annually with predominantly loam soil. Summer highs average 93ยฐF, providing good warmth for Shiso during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Shiso root diseases.

Concho County, TX (Zone 8a) Long season
232 days
Last Spring Frost March 25
232 growing days
First Fall Frost November 12

Concho County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (113 days to spare)
Start indoors: Jan 22 Transplant: Mar 26 🍅 Harvest: May 21 – Jul 16
Recommended (50%) ✓ Fits season (106 days to spare)
Start indoors: Feb 4 Transplant: Apr 8 🍅 Harvest: Jun 3 – Jul 29
Safe Start (90%) ✓ Fits season (106 days to spare)
Start indoors: Feb 23 Transplant: Apr 27 🍅 Harvest: Jun 22 – Aug 17

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 Concho County

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

Soil pH

Your soil pH (6.6โ€“7.4) overlaps with Shiso's range (5.5โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.0%). 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 232-day season

Sow every 5.7 weeks. Last sowing by Sep 03 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
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 2.2" 0" โ„๏ธ Dormant
Mar 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Apr 4.3" 6.8" 0" โœ… Rainfall sufficient
May 4.3" 8.9" 0" โœ… Rainfall sufficient
Jun 4.3" 9.3" 0" โœ… Rainfall sufficient
Jul 4.3" 6.8" 0" โœ… Rainfall sufficient
Aug 4.3" 6.5" 0" โœ… Rainfall sufficient
Sep 4.3" 5.4" 0" โœ… Rainfall sufficient
Oct 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Nov 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
Dec โ€” 1.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Concho 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 4,582 GDD Excellent fit

Shiso Planting Timeline โ€” Concho County, TX

Shiso Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 โ€“ Feb 18
Transplant Outdoors April 8 Apr 8 โ€“ Apr 22
Direct Sow April 1 Apr 1 โ€“ Apr 22
Harvest June 3 Jun 3 โ€“ Jul 29

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 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 8a

๐Ÿ“† Growing Season

232 days in Concho County

Growing Tips for Shiso in Concho County

Direct sow Shiso outdoors after March 25 in Concho 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 Concho County, TX?

Concho County is in Zone 8a with an average last frost of March 25. Plan your Shiso planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Concho County, TX?

Concho County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Concho County gardeners in Zone 8a 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 Concho County, TX. Local conditions may vary. Last updated: April 2026.