Blog

When to Plant Shiso in Lamar 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.

Lamar County, Texas is in USDA Zone 7b. The average last spring frost is March 15 and the first fall frost is November 15, giving you a growing season of approximately 245 days.

At an elevation of 95 feet, Lamar County receives approximately 59.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 91ยฐF, providing good warmth for Shiso during the growing season. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Shiso will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Shiso root diseases.

Lamar County, TX (Zone 7b) Long season
245 days
Last Spring Frost March 15
245 growing days
First Fall Frost November 15

Lamar County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (115 days to spare)
Start indoors: Jan 17 Transplant: Mar 21 🍅 Harvest: May 16 – Jul 11
Recommended (50%) ✓ Fits season (119 days to spare)
Start indoors: Jan 25 Transplant: Mar 29 🍅 Harvest: May 24 – Jul 19
Safe Start (90%) ✓ Fits season (109 days to spare)
Start indoors: Feb 19 Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 13

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 Lamar County

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

Soil pH

Your soil pH (5.8โ€“6.8) is within Shiso's preferred range (5.5โ€“7.0).

Soil Texture

Sandy soil in Lamar County warms quickly in spring but drains fast. Shiso will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (1.9%). Add 2-3 inches of compost before planting Shiso.

How to Plant Shiso

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

Succession Planting Shiso

5
successive plantings in your 245-day season

Sow every 5.7 weeks. Last sowing by Sep 06 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€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 2.1" 0" โ„๏ธ Dormant
Mar 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Apr 4.3" 6.8" 0" โœ… Rainfall sufficient
May 4.3" 8.8" 0" โœ… Rainfall sufficient
Jun 4.3" 9.7" 0" โœ… Rainfall sufficient
Jul 4.3" 8" 0" โœ… Rainfall sufficient
Aug 4.3" 7.1" 0" โœ… Rainfall sufficient
Sep 4.3" 5.3" 0" โœ… Rainfall sufficient
Oct 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Nov 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
Dec โ€” 1.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Lamar 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 ~1,095 GDD — county provides 4,471 GDD Excellent fit

Shiso Planting Timeline โ€” Lamar County, TX

Shiso Planting Calendar

Activity When Date Range
Start Indoors January 25 Jan 25 โ€“ Feb 8
Transplant Outdoors March 29 Mar 29 โ€“ Apr 12
Direct Sow March 22 Mar 22 โ€“ Apr 12
Harvest May 24 May 24 โ€“ Jul 19

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: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

245 days in Lamar County

Growing Tips for Shiso in Lamar County

Direct sow Shiso outdoors after March 15 in Lamar County when soil has warmed and frost danger has passed.

Sandy soil in Lamar County dries quickly โ€” mulch Shiso with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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 Lamar County, TX?

Lamar County is in Zone 7b with an average last frost of March 15. Plan your Shiso planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lamar County, TX?

Lamar County, Texas is in USDA Hardiness Zone 7b. The average last spring frost is March 15 and first fall frost is November 15.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lamar 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 Lamar County, TX. Local conditions may vary. Last updated: April 2026.