Blog

When to plant Basil in Franklin County, ME

Franklin County's short 137-day growing season means one Basil planting between May 21 and June 11. No fall crop in Zone 5a.

When to Plant Basil in Franklin County, ME

Basil
Franklin County, Maine Zone 5a June

June in the garden — Franklin County, Maine

Here's what deserves your attention in Franklin County, Maine this month. Everything below is tailored to Zone 5a and timed around your local frost dates.

Avg. last frost May 14
Avg. first frost September 28
Soil temp (4") 63°F
Watering Moderate
Pest pressure High
Daylight 15.4 hrs
Get ahead of July
  • Starting indoors: basil
  • First harvests: basil

Instant PDF download. No spam, unsubscribe any time.

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.

Franklin County, Maine is in USDA Zone 5a. The average last spring frost is May 14 and the first fall frost is September 28, giving you a growing season of approximately 137 days.

At an elevation of 244 feet, Franklin County receives approximately 40.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Basil to ensure they mature before fall.

Franklin County, ME (Zone 5a) Short season
137 days
Last Spring Frost May 14
137 growing days
First Fall Frost September 28

Franklin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.6

Drainage

Well Drained

Basil Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 23 Transplant: May 25 🍅 Harvest: Jul 20 – Sep 21
Recommended (50%) ✓ Fits season (4 days to spare)
Start indoors: Mar 26 Transplant: May 28 🍅 Harvest: Jul 23 – Sep 24
Safe Start (90%) ✓ Fits season (0 days to spare)
Start indoors: Apr 12 Transplant: Jun 14 🍅 Harvest: Aug 9 – Oct 11

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 Franklin County

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

Soil pH

Your soil pH (5.2–6.6) is more acidic than Basil prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Basil.

How to Plant Basil

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

Succession Planting Basil

3
successive plantings in your 137-day season

Sow every 5.7 weeks. Last sowing by Jul 15 to harvest before frost.

Basil Water Budget

Plant needs
0.6″/week
Rainfall provides
1.3″/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 3.2" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 3.9" 0" ❄️ Dormant
Apr 3.1" 0" ❄️ Dormant
May 2.6" 4.1" 0" ✅ Rainfall sufficient
Jun 2.6" 3.4" 0" ✅ Rainfall sufficient
Jul 2.6" 4.1" 0" ✅ Rainfall sufficient
Aug 2.6" 4.1" 0" ✅ Rainfall sufficient
Sep 2.6" 3" 0" ✅ Rainfall sufficient
Oct 3.4" 0" ❄️ Dormant
Nov 2.7" 0" ❄️ Dormant
Dec 3.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Franklin County). 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 ~625 GDD — county provides 1,370 GDD Excellent fit

Basil Planting Timeline — Franklin County, ME

Basil Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors May 28 May 28 – Jun 11
Direct Sow May 21 May 21 – Jun 11
Harvest July 23 Jul 23 – Sep 24

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

Month-by-Month Timeline

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

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: too_acidic

🗺️ USDA Zone

Zone 5a

📆 Growing Season

137 days in Franklin County

Growing Tips for Basil in Franklin County

Direct sow Basil outdoors after May 14 in Franklin County 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 Franklin County, ME?

Franklin County is in Zone 5a with an average last frost of May 14. Plan your Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Franklin County, ME?

Franklin County, Maine is in USDA Hardiness Zone 5a. The average last spring frost is May 14 and first fall frost is September 28.

When should I plant Basil in Franklin County, ME?

In Franklin County, ME, plant Basil after the last frost (around May 14) and before the first frost (around September 28). Best results when soil holds above 50°F.

What growing zone is Franklin County, ME for Basil?

Franklin County sits in USDA Zone 5a. Basil grows reliably in zones 4a through 11b, so it's a good fit here.

Can Basil grow in Franklin County's climate?

Yes — Basil grows well in Franklin County's temperate climate. Franklin County averages a 137-day frost-free season, with last frost around May 14 and first frost around September 28.

🌱

Your Franklin County Garden Planner — Free

A 22-page printable planner built for Franklin County (Zone 5a). 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 Franklin County, ME. Local conditions may vary. Last updated: June 2026.

Sources & credits

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