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When to Plant Shiso in Middlesex County, VA

Middlesex County, Virginia Zone 8a May

Top priorities for Middlesex County, Virginia gardeners in May

A quick May briefing for Middlesex County, Virginia gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 1
Avg. first frost November 4
Soil temp (4") 69°F
Watering Moderate
Pest pressure Moderate
Daylight 14 hrs
  1. Begin indoor sowing: shiso

    These need a head start before your last frost (April 1). Sow into cells now so you're ready to transplant in a few weeks.

Get ahead of June
  • 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.

Middlesex County, Virginia is in USDA Zone 8a. The average last spring frost is April 1 and the first fall frost is November 4, giving you a growing season of approximately 217 days.

At an elevation of 812 feet, Middlesex County receives approximately 41.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Shiso during the growing season.

Middlesex County, VA (Zone 8a) Long season
217 days
Last Spring Frost April 1
217 growing days
First Fall Frost November 4

Middlesex County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (96 days to spare)
Start indoors: Feb 3 Transplant: Apr 7 🍅 Harvest: Jun 2 – Jul 28
Recommended (50%) ✓ Fits season (91 days to spare)
Start indoors: Feb 11 Transplant: Apr 15 🍅 Harvest: Jun 10 – Aug 5
Safe Start (90%) ✓ Fits season (89 days to spare)
Start indoors: Feb 28 Transplant: May 2 🍅 Harvest: Jun 27 – Aug 22

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 Middlesex County

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

Soil pH

Your soil pH (5.7–7.1) overlaps with Shiso's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Shiso.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Shiso.

How to Plant Shiso

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

Succession Planting Shiso

5
successive plantings in your 217-day season

Sow every 5.7 weeks. Last sowing by Aug 26 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 3.8" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 4.4" 0" ❄️ Dormant
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 3.5" 0.8" 💧 Light watering
Jun 4.3" 3.3" 1" 💧 Light watering
Jul 4.3" 4.7" 0" ✅ Rainfall sufficient
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 4.3" 2.9" 1.4" 💧 Light watering
Dec 3.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Middlesex 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 ~1,005 GDD — county provides 3,634 GDD Excellent fit

Shiso Planting Timeline — Middlesex County, VA

Shiso Planting Calendar

Activity When Date Range
Start Indoors February 11 Feb 11 – Feb 25
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow April 8 Apr 8 – Apr 29
Harvest June 10 Jun 10 – Aug 5

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
April Transplant Outdoors Direct Sow
May
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: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

217 days in Middlesex County

Growing Tips for Shiso in Middlesex County

Direct sow Shiso outdoors after April 01 in Middlesex 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 Middlesex County, VA?

Middlesex County is in Zone 8a with an average last frost of April 1. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Middlesex County, VA?

Middlesex County, Virginia is in USDA Hardiness Zone 8a. The average last spring frost is April 1 and first fall frost is November 4.

🌱

Your Middlesex County Garden Planner — Free

A 24-page printable planner built for Middlesex County (Zone 8a). 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 Middlesex County, VA. 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.