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When to Plant Shiso in Barnes County, ND

Barnes County, North Dakota Zone 4a May

Barnes County, North Dakota gardeners: here's your May plan

Each item below is timed to Barnes County, North Dakota's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 9
Avg. first frost September 29
Soil temp (4") 55°F
Watering Moderate
Pest pressure Low
Daylight 14.8 hrs
  1. Plant out shiso

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Sow shiso where they'll grow

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

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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.

Barnes County, North Dakota is in USDA Zone 4a. The average last spring frost is May 9 and the first fall frost is September 29, giving you a growing season of approximately 143 days.

At an elevation of 623 feet, Barnes County receives approximately 20.5 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Shiso to ensure they mature before fall.

Barnes County, ND (Zone 4a) Short season
143 days
Last Spring Frost May 9
143 growing days
First Fall Frost September 29
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Barnes County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Start indoors: Mar 6 Transplant: May 22 🍅 Harvest: Jul 17 – Sep 11
Recommended (50%) ✓ Fits season (10 days to spare)
Start indoors: Mar 14 Transplant: May 30 🍅 Harvest: Jul 25 – Sep 19
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: Mar 24 Transplant: Jun 9 🍅 Harvest: Aug 4 – Sep 29

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 Barnes County

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

Soil pH

Your soil pH (6.3–7.7) overlaps with Shiso's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). Annual compost additions will help Shiso.

How to Plant Shiso

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

Succession Planting Shiso

3
successive plantings in your 143-day season

Sow every 5.7 weeks. Last sowing by Jul 21 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 506 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 0.5" 0" ❄️ Dormant
Feb 0.6" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 2.8" 1.5" 💧 Light watering
Jul 4.3" 3" 1.3" 💧 Light watering
Aug 4.3" 2.6" 1.7" 💧 Light watering
Sep 4.3" 1.9" 2.4" 🚿 Regular watering
Oct 1.1" 0" ❄️ Dormant
Nov 0.8" 0" ❄️ Dormant
Dec 0.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Barnes 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 ~780 GDD — county provides 1,859 GDD Excellent fit

Shiso Planting Timeline — Barnes County, ND

Shiso Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors May 30 May 30 – Jun 13
Direct Sow May 16 May 16 – Jun 6
Harvest July 25 Jul 25 – Sep 19

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors 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 · 1-2 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

143 days in Barnes County

Growing Tips for Shiso in Barnes County

Direct sow Shiso outdoors after May 09 in Barnes County when soil has warmed and frost danger has passed.

Barnes County receives only 20" 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 Barnes County, ND?

Barnes County is in Zone 4a with an average last frost of May 9. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Barnes County, ND?

Barnes County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 9 and first fall frost is September 29.

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Your Barnes County Garden Planner — Free

A 24-page printable planner built for Barnes County (Zone 4a). 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 Barnes County, ND. 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.