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When to Plant Shiso in Atchison County, KS

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.

Atchison County, Kansas is in USDA Zone 5b. The average last spring frost is April 17 and the first fall frost is October 21, giving you a growing season of approximately 187 days.

At an elevation of 678 feet, Atchison County receives approximately 25.2 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.

Atchison County, KS (Zone 5b) Moderate season
187 days
Last Spring Frost April 17
187 growing days
First Fall Frost October 21

Atchison County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (56 days to spare)
Start indoors: Feb 22 Transplant: Apr 26 🍅 Harvest: Jun 21 – Aug 16
Recommended (50%) ✓ Fits season (61 days to spare)
Start indoors: Feb 27 Transplant: May 1 🍅 Harvest: Jun 26 – Aug 21
Safe Start (90%) ✓ Fits season (65 days to spare)
Start indoors: Mar 14 Transplant: May 16 🍅 Harvest: Jul 11 – Sep 5

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 Atchison County

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

Soil pH

Your soil pH (6.4โ€“7.8) is more alkaline than Shiso prefers (5.5โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Atchison County is excellent for Shiso โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Shiso.

Organic Matter

Organic matter is moderate (3.5%). Annual compost additions will help Shiso.

How to Plant Shiso

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

Succession Planting Shiso

4
successive plantings in your 187-day season

Sow every 5.7 weeks. Last sowing by Aug 12 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,466 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 0.6" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.8" 0" โ„๏ธ Dormant
Apr 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering
May 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Jun 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Jul 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Aug 4.3" 2.9" 1.4" ๐Ÿ’ง Light watering
Sep 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Oct 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Nov โ€” 0.9" 0" โ„๏ธ Dormant
Dec โ€” 0.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Atchison 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 ~780 GDD — county provides 2,431 GDD Excellent fit

Shiso Planting Timeline โ€” Atchison County, KS

Shiso Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 โ€“ Mar 13
Transplant Outdoors May 1 May 1 โ€“ May 15
Direct Sow April 24 Apr 24 โ€“ May 15
Harvest June 26 Jun 26 โ€“ Aug 21

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

50โ€“70 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

187 days in Atchison County

Growing Tips for Shiso in Atchison County

Direct sow Shiso outdoors after April 17 in Atchison 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 Atchison County, KS?

Atchison County is in Zone 5b with an average last frost of April 17. Plan your Shiso planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Atchison County, KS?

Atchison County, Kansas is in USDA Hardiness Zone 5b. The average last spring frost is April 17 and first fall frost is October 21.

๐ŸŒฑ

Plan Your Garden with Confidence

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