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When to Plant Shiso in Laramie County, WY

Laramie County, Wyoming Zone 5b May

This month in Laramie County, Wyoming

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 19
Avg. first frost September 24
Soil temp (4") 39°F
Watering High
Pest pressure Low
Daylight 14.3 hrs
  1. Scatter shiso into prepared beds

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

Coming up in June — start thinking about
  • Transplants going out: shiso

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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.

Laramie County, Wyoming is in USDA Zone 5b. The average last spring frost is May 19 and the first fall frost is September 24, giving you a growing season of approximately 128 days.

At an elevation of 6,153 feet, Laramie County receives approximately 19.3 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Shiso to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Shiso successfully. Mulch heavily to conserve soil moisture.

Laramie County, WY (Zone 5b) Short season
128 days
Last Spring Frost May 19
128 growing days
First Fall Frost September 24
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Laramie County Soil Profile

Soil Type

Loam

Soil pH

6.5-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (2 days to spare)
Start indoors: Mar 24 Transplant: May 26 🍅 Harvest: Jul 21 – Sep 15
Recommended (50%) ✓ Fits season (2 days to spare)
Start indoors: Mar 31 Transplant: Jun 2 🍅 Harvest: Jul 28 – Sep 22
Safe Start (90%) ✗ May not fit
Start indoors: Apr 19 Transplant: Jun 21 🍅 Harvest: Aug 16 – Oct 11

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 Laramie County

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

Soil pH

Your soil pH (6.5–8.2) is more alkaline than Shiso prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Laramie County is excellent for Shiso — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Shiso.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Shiso.

How to Plant Shiso

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

Succession Planting Shiso

2
successive plantings in your 128-day season

Sow every 5.7 weeks. Last sowing by Jul 16 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 911 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.4" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 1.9" 0" ❄️ Dormant
May 4.3" 2.1" 2.2" 🚿 Regular watering
Jun 4.3" 1.3" 3" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 2" 2.3" 🚿 Regular watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 1.7" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Laramie County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~735 GDD — county provides 1,568 GDD Excellent fit

Shiso Planting Timeline — Laramie County, WY

Shiso Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 – Apr 14
Transplant Outdoors June 2 Jun 2 – Jun 16
Direct Sow May 26 May 26 – Jun 16
Harvest July 28 Jul 28 – Sep 22

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

128 days in Laramie County

Growing Tips for Shiso in Laramie County

Direct sow Shiso outdoors after May 19 in Laramie County when soil has warmed and frost danger has passed.

Laramie County receives only 19" of rain annually. Shiso needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Laramie County, WY?

Laramie County is in Zone 5b with an average last frost of May 19. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Laramie County, WY?

Laramie County, Wyoming is in USDA Hardiness Zone 5b. The average last spring frost is May 19 and first fall frost is September 24.

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Your Laramie County Garden Planner — Free

A 24-page printable planner built for Laramie County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Laramie County, WY. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.