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When to Plant Shiso in Howard County, NE

Howard County, Nebraska Zone 5b May

Howard County, Nebraska gardeners: here's your May plan

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 28
Avg. first frost October 7
Soil temp (4") 60°F
Watering Moderate
Pest pressure Low
Daylight 14.3 hrs
  1. Transplant shiso outside

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Outdoor sowing time: shiso

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

Coming up in June — start thinking about
  • Starting indoors: 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.

Howard County, Nebraska is in USDA Zone 5b. The average last spring frost is April 28 and the first fall frost is October 7, giving you a growing season of approximately 162 days.

At an elevation of 844 feet, Howard County receives approximately 20.4 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Shiso to ensure they mature before fall.

Howard County, NE (Zone 5b) Moderate season
162 days
Last Spring Frost April 28
162 growing days
First Fall Frost October 7

Howard County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (37 days to spare)
Start indoors: Mar 4 Transplant: May 6 🍅 Harvest: Jul 1 – Aug 26
Recommended (50%) ✓ Fits season (36 days to spare)
Start indoors: Mar 10 Transplant: May 12 🍅 Harvest: Jul 7 – Sep 1
Safe Start (90%) ✓ Fits season (36 days to spare)
Start indoors: Mar 26 Transplant: May 28 🍅 Harvest: Jul 23 – Sep 17

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 Howard County

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

Soil pH

Your soil pH (6.7–7.8) is more alkaline than Shiso prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Shiso will thrive.

How to Plant Shiso

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

Succession Planting Shiso

3
successive plantings in your 162-day season

Sow every 5.7 weeks. Last sowing by Jul 29 to harvest before frost.

Plant 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 815 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 0.5" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 4.3" 2.3" 2" 💧 Light watering
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 3.1" 1.2" 💧 Light watering
Jul 4.3" 2.3" 2" 💧 Light watering
Aug 4.3" 2.3" 2" 💧 Light watering
Sep 4.3" 2.1" 2.2" 🚿 Regular watering
Oct 4.3" 1.2" 3.1" 🚿 Regular watering
Nov 0.7" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Howard 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 ~735 GDD — county provides 1,984 GDD Excellent fit

Shiso Planting Timeline — Howard County, NE

Shiso Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors May 12 May 12 – May 26
Direct Sow May 5 May 5 – May 26
Harvest July 7 Jul 7 – Sep 1

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
July Harvest
August Harvest
September Harvest
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 5b

📆 Growing Season

162 days in Howard County

Growing Tips for Shiso in Howard County

Direct sow Shiso outdoors after April 28 in Howard County when soil has warmed and frost danger has passed.

Howard 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 Howard County, NE?

Howard County is in Zone 5b with an average last frost of April 28. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Howard County, NE?

Howard County, Nebraska is in USDA Hardiness Zone 5b. The average last spring frost is April 28 and first fall frost is October 7.

🌱

Your Howard County Garden Planner — Free

A 24-page printable planner built for Howard County (Zone 5b). 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 Howard County, NE. 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.