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When to Plant Shiso in Pacific County, WA

Pacific County, Washington Zone 9a July

July in Pacific County, Washington — your action list

Your garden in Pacific County, Washington is working on a schedule, even when you're not. Here's where you should be this July.

Avg. last frost April 18
Avg. first frost October 29
Soil temp (4") 90°F
Watering Critical
Pest pressure High
Daylight 15.3 hrs
  1. Collect shiso at their peak

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Coming up in August — start thinking about
  • 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.

Pacific County, Washington is in USDA Zone 9a. The average last spring frost is April 18 and the first fall frost is October 29, giving you a growing season of approximately 194 days.

At an elevation of 14 feet, Pacific County receives approximately 47.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Shiso during the growing season.

Pacific County, WA (Zone 9a) Moderate season
194 days
Last Spring Frost April 18
194 growing days
First Fall Frost October 29

Pacific County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Shiso Planting Risk Windows

Early Start (70% safe) ✓ Fits season (75 days to spare)
Start indoors: Feb 22 Transplant: Apr 12 🍅 Harvest: Jun 7 – Aug 2
Recommended (50%) ✓ Fits season (75 days to spare)
Start indoors: Mar 7 Transplant: Apr 25 🍅 Harvest: Jun 20 – Aug 15
Safe Start (90%) ✓ Fits season (88 days to spare)
Start indoors: Mar 28 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 Pacific County

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

Soil pH

Your soil pH (5.6–6.2) is within Shiso's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.5%) — 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 194-day season

Sow every 5.7 weeks. Last sowing by Aug 20 to harvest before frost.

Shiso Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 7.2" 0" ❄️ Dormant
Feb 5" 0" ❄️ Dormant
Mar 4.5" 0" ❄️ Dormant
Apr 4.3" 3.8" 0.5" 💧 Light watering
May 4.3" 2.8" 1.5" 💧 Light watering
Jun 4.3" 1.8" 2.5" 🚿 Regular watering
Jul 4.3" 0.9" 3.4" 🚿 Regular watering
Aug 4.3" 0.9" 3.4" 🚿 Regular watering
Sep 4.3" 1.7" 2.6" 🚿 Regular watering
Oct 4.3" 4.2" 0.1" 💧 Light watering
Nov 8" 0" ❄️ Dormant
Dec 6.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Pacific 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 ~870 GDD — county provides 2,813 GDD Excellent fit

Shiso Planting Timeline — Pacific County, WA

Shiso Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 – Mar 21
Transplant Outdoors April 25 Apr 25 – May 9
Direct Sow April 25 Apr 25 – May 16
Harvest June 20 Jun 20 – Aug 15

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

Month-by-Month Timeline

MonthActivities
January
February
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 · Natural rainfall sufficient

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 9a

📆 Growing Season

194 days in Pacific County

Growing Tips for Shiso in Pacific County

Direct sow Shiso outdoors after April 18 in Pacific 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 Pacific County, WA?

Pacific County is in Zone 9a with an average last frost of April 18. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pacific County, WA?

Pacific County, Washington is in USDA Hardiness Zone 9a. The average last spring frost is April 18 and first fall frost is October 29.

🌱

Your Pacific County Garden Planner — Free

A 22-page printable planner built for Pacific County (Zone 9a). 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 Pacific County, WA. 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.