Blog

When to plant Shiso in Ottawa County, KS

Plant Shiso in Ottawa County from April 21 to May 12 in spring. Ottawa County sits in USDA Zone 6b, with last frost around April 14 and first frost on October 23.

When to Plant Shiso in Ottawa County, KS

Ottawa County, Kansas Zone 6b July

Your July planting checklist for Ottawa County, Kansas

Here's what deserves your attention in Ottawa County, Kansas this month. Everything below is tailored to Zone 6b and timed around your local frost dates.

Avg. last frost April 14
Avg. first frost October 23
Soil temp (4") 77°F
Watering Moderate
Pest pressure High
Daylight 14.5 hrs
  1. Pick shiso

    If you can't use it all right away, check the food-preservation section of your planner.

Before August arrives, get these ready
  • First harvests: shiso

Instant PDF download. No spam, unsubscribe any time.

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.

Ottawa County, Kansas is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 23, giving you a growing season of approximately 192 days.

At an elevation of 993 feet, Ottawa County receives approximately 24 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Shiso during the growing season.

Ottawa County, KS (Zone 6b) Moderate season
192 days
Last Spring Frost April 14
192 growing days
First Fall Frost October 23

Ottawa County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.6

Drainage

Well Drained

Shiso Planting Risk Windows

Early Start (70% safe) ✓ Fits season (60 days to spare)
Start indoors: Feb 21 Transplant: Apr 25 🍅 Harvest: Jun 20 – Aug 15
Recommended (50%) ✓ Fits season (66 days to spare)
Start indoors: Feb 24 Transplant: Apr 28 🍅 Harvest: Jun 23 – Aug 18
Safe Start (90%) ✓ Fits season (63 days to spare)
Start indoors: Mar 9 Transplant: May 11 🍅 Harvest: Jul 6 – Aug 31

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 Ottawa County

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

Soil pH

Your soil pH (6.8–7.6) is more alkaline than Shiso prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — 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 192-day season

Sow every 5.7 weeks. Last sowing by Aug 14 to harvest before frost.

Shiso Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 974 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 0.7" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 4.3" 2.4" 1.9" 💧 Light watering
May 4.3" 3.5" 0.8" 💧 Light watering
Jun 4.3" 3.5" 0.8" 💧 Light watering
Jul 4.3" 3.1" 1.2" 💧 Light watering
Aug 4.3" 2.9" 1.4" 💧 Light watering
Sep 4.3" 2.3" 2" 💧 Light watering
Oct 4.3" 1.7" 2.6" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Ottawa 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 2,640 GDD Excellent fit

Shiso Planting Timeline — Ottawa County, KS

Shiso Planting Calendar

Activity When Date Range
Start Indoors February 24 Feb 24 – Mar 10
Transplant Outdoors April 28 Apr 28 – May 12
Direct Sow April 21 Apr 21 – May 12
Harvest June 23 Jun 23 – Aug 18

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April Transplant Outdoors 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

192 days in Ottawa County

Growing Tips for Shiso in Ottawa County

Direct sow Shiso outdoors after April 14 in Ottawa County when soil has warmed and frost danger has passed.

Ottawa County receives only 24" 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 Ottawa County, KS?

Ottawa County is in Zone 6b with an average last frost of April 14. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ottawa County, KS?

Ottawa County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 23.

When should I plant Shiso in Ottawa County, KS?

In Ottawa County, KS, plant Shiso after the last frost (around April 14) and before the first frost (around October 23). Best results when soil holds above 50°F.

What growing zone is Ottawa County, KS for Shiso?

Ottawa County sits in USDA Zone 6b. Shiso grows reliably in zones 3a through 11b, so it's a good fit here.

Can Shiso grow in Ottawa County's climate?

Yes — Shiso grows well in Ottawa County's temperate climate. Ottawa County averages a 192-day frost-free season, with last frost around April 14 and first frost around October 23.

🌱

Your Ottawa County Garden Planner — Free

A 22-page printable planner built for Ottawa 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Ottawa County, KS. Local conditions may vary. Last updated: July 2026.

Sources & credits

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