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When to Plant Shiso in Garfield County, UT

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.

Garfield County, Utah is in USDA Zone 5b. The average last spring frost is May 27 and the first fall frost is September 21, giving you a growing season of approximately 117 days.

At an elevation of 5,058 feet, Garfield County receives approximately 20.3 inches of rainfall annually with predominantly loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Shiso to ensure they mature before fall.

Garfield County, UT (Zone 5b) Short season
117 days
Last Spring Frost May 27
117 growing days
First Fall Frost September 21

Garfield County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 27 Transplant: May 29 🍅 Harvest: Jul 24 – Sep 18
Recommended (50%) ✗ May not fit
Start indoors: Apr 8 Transplant: Jun 10 🍅 Harvest: Aug 5 – Sep 30
Safe Start (90%) ✗ May not fit
Start indoors: May 6 Transplant: Jul 8 🍅 Harvest: Sep 2 – Oct 28

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 339 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Shiso needs ~780 GDD — county provides 1,521 GDD Excellent fit

Shiso Planting Timeline โ€” Garfield County, UT

Shiso Planting Calendar

Activity When Date Range
Start Indoors April 8 Apr 8 โ€“ Apr 22
Transplant Outdoors June 10 Jun 10 โ€“ Jun 24
Direct Sow June 3 Jun 3 โ€“ Jun 24
Harvest August 5 Aug 5 โ€“ Sep 30

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

50โ€“70 days

Soil pH

5.5 โ€“ 7

USDA Zone

Zone 5b

Growing Season

117 days

Growing Tips for Garfield County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Shiso in Garfield County, UT?

Garfield County is in Zone 5b with an average last frost of May 27. Plan your Shiso planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Garfield County, UT?

Garfield County, Utah is in USDA Hardiness Zone 5b. The average last spring frost is May 27 and first fall frost is September 21.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Garfield County gardeners in Zone 5b 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 Garfield County, UT. Local conditions may vary. Last updated: April 2026.