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When to Plant Shiso in Grant County, KS

Grant County, Kansas Zone 6b May

May in the garden — Grant County, Kansas

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

Avg. last frost April 21
Avg. first frost October 17
Soil temp (4") 62°F
Watering Moderate
Pest pressure Low
Daylight 14 hrs
  1. Move shiso from tray to bed

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

June prep starts now
  • Starting indoors: shiso
  • First harvests: 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.

Grant County, Kansas is in USDA Zone 6b. The average last spring frost is April 21 and the first fall frost is October 17, giving you a growing season of approximately 179 days.

At an elevation of 1,096 feet, Grant County receives approximately 25.2 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Shiso during the growing season.

Grant County, KS (Zone 6b) Moderate season
179 days
Last Spring Frost April 21
179 growing days
First Fall Frost October 17

Grant County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Start indoors: Feb 26 Transplant: Apr 30 🍅 Harvest: Jun 25 – Aug 20
Recommended (50%) ✓ Fits season (53 days to spare)
Start indoors: Mar 3 Transplant: May 5 🍅 Harvest: Jun 30 – Aug 25
Safe Start (90%) ✓ Fits season (55 days to spare)
Start indoors: Mar 16 Transplant: May 18 🍅 Harvest: Jul 13 – Sep 7

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 Grant County

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

Soil pH

Your soil pH (6.4–7.7) is more alkaline than Shiso prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — Shiso will thrive.

How to Plant Shiso

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

Succession Planting Shiso

4
successive plantings in your 179-day season

Sow every 5.7 weeks. Last sowing by Aug 08 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 781 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 1.8" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 2.8" 1.5" 💧 Light watering
Jun 4.3" 1.9" 2.4" 🚿 Regular watering
Jul 4.3" 2" 2.3" 🚿 Regular watering
Aug 4.3" 2.7" 1.6" 💧 Light watering
Sep 4.3" 2.4" 1.9" 💧 Light watering
Oct 4.3" 2.1" 2.2" 🚿 Regular watering
Nov 1.6" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Grant 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 ~825 GDD — county provides 2,461 GDD Excellent fit

Shiso Planting Timeline — Grant County, KS

Shiso Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 – Mar 17
Transplant Outdoors May 5 May 5 – May 19
Direct Sow April 28 Apr 28 – May 19
Harvest June 30 Jun 30 – Aug 25

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

Month-by-Month Timeline

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

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: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

179 days in Grant County

Growing Tips for Shiso in Grant County

Direct sow Shiso outdoors after April 21 in Grant 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 Grant County, KS?

Grant County is in Zone 6b with an average last frost of April 21. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grant County, KS?

Grant County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 21 and first fall frost is October 17.

🌱

Your Grant County Garden Planner — Free

A 24-page printable planner built for Grant County (Zone 6b). 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 Grant County, KS. 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.