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When to Plant Basil in Portsmouth City, VA

Portsmouth City, Virginia Zone 8b May

Top priorities for Portsmouth City, Virginia gardeners in May

Here's what deserves your attention in Portsmouth City, Virginia this month. Everything below is tailored to Zone 8b and timed around your local frost dates.

Avg. last frost March 22
Avg. first frost November 17
Soil temp (4") 71°F
Watering Moderate
Pest pressure High
Daylight 14 hrs
  1. Start basil under lights

    You're about 28 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Collect basil at their peak

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

A few tasks this May that'll pay off in June
  • First harvests: basil

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Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.

Portsmouth City, Virginia is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 17, giving you a growing season of approximately 240 days.

At an elevation of 594 feet, Portsmouth City receives approximately 41.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Basil during the growing season.

Portsmouth City, VA (Zone 8b) Long season
240 days
Last Spring Frost March 22
240 growing days
First Fall Frost November 17
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Portsmouth City Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (105 days to spare)
Start indoors: Jan 26 Transplant: Mar 30 🍅 Harvest: May 25 – Jul 27
Recommended (50%) ✓ Fits season (107 days to spare)
Start indoors: Feb 1 Transplant: Apr 5 🍅 Harvest: May 31 – Aug 2
Safe Start (90%) ✓ Fits season (91 days to spare)
Start indoors: Mar 5 Transplant: May 7 🍅 Harvest: Jul 2 – Sep 3

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 Portsmouth City

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

Soil pH

Your soil pH (5.4–7.0) overlaps with Basil's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Portsmouth City is excellent for Basil — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Basil.

How to Plant Basil

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

Succession Planting Basil

5
successive plantings in your 240-day season

Sow every 5.7 weeks. Last sowing by Sep 03 to harvest before frost.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Basil

Basil needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Basil Needs Rainfall You Supplement Action
Jan 3.4" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 2.6" 4.4" 0" ✅ Rainfall sufficient
Apr 2.6" 2.8" 0" ✅ Rainfall sufficient
May 2.6" 3" 0" ✅ Rainfall sufficient
Jun 2.6" 4" 0" ✅ Rainfall sufficient
Jul 2.6" 4" 0" ✅ Rainfall sufficient
Aug 2.6" 4.4" 0" ✅ Rainfall sufficient
Sep 2.6" 3" 0" ✅ Rainfall sufficient
Oct 2.6" 2.9" 0" ✅ Rainfall sufficient
Nov 2.6" 3" 0" ✅ Rainfall sufficient
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Portsmouth City). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Basil 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.

Basil needs ~1,234 GDD — county provides 4,740 GDD Excellent fit

Basil Planting Timeline — Portsmouth City, VA

Basil Planting Calendar

Activity When Date Range
Start Indoors February 1 Feb 1 – Feb 15
Transplant Outdoors April 5 Apr 5 – Apr 19
Direct Sow March 29 Mar 29 – Apr 19
Harvest May 31 May 31 – Aug 2

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.6"/week · Natural rainfall sufficient

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

240 days in Portsmouth City

Growing Tips for Basil in Portsmouth City

Direct sow Basil outdoors after March 22 in Portsmouth City when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors or direct sow after last frost. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.

Companion Planting

Good Companions

Avoid Planting Near

  • Rue
  • Sage

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Basil Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let flower spikes dry brown on the plant.
Storage Store airtight; viable 5 years at 35°F, under 45% humidity.

Isolate 150 ft between varieties. Different basil species can cross.

Frequently Asked Questions

When should I plant Basil in Portsmouth City, VA?

Portsmouth City is in Zone 8b with an average last frost of March 22. Plan your Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Portsmouth City, VA?

Portsmouth City, Virginia is in USDA Hardiness Zone 8b. The average last spring frost is March 22 and first fall frost is November 17.

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Your Portsmouth City Garden Planner — Free

A 24-page printable planner built for Portsmouth City (Zone 8b). 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 Portsmouth City, 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.