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When to Plant Basil in Shoshone County, ID

Shoshone County, Idaho Zone 6b May

Your May gardening checklist

Welcome to May in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 10
Avg. first frost September 26
Soil temp (4") 41°F
Watering High
Pest pressure Low
Daylight 14.9 hrs
  1. Time to transplant basil

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Sow basil where they'll grow

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

Get ahead of June
  • Starting indoors: 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.

Shoshone County, Idaho is in USDA Zone 6b. The average last spring frost is May 10 and the first fall frost is September 26, giving you a growing season of approximately 139 days.

At an elevation of 6,353 feet, Shoshone County receives approximately 14.1 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Basil to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Basil successfully. Mulch heavily to conserve soil moisture.

Shoshone County, ID (Zone 6b) Short season
139 days
Last Spring Frost May 10
139 growing days
First Fall Frost September 26
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Shoshone County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (1 days to spare)
Start indoors: Mar 15 Transplant: May 17 🍅 Harvest: Jul 12 – Sep 13
Recommended (50%) ✓ Fits season (6 days to spare)
Start indoors: Mar 22 Transplant: May 24 🍅 Harvest: Jul 19 – Sep 20
Safe Start (90%) ✓ Fits season (9 days to spare)
Start indoors: Apr 16 Transplant: Jun 18 🍅 Harvest: Aug 13 – Oct 15

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 Shoshone County

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

Soil pH

Your soil pH (6.6–7.7) is more alkaline than Basil prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Basil.

Organic Matter

Organic matter is moderate (2.8%). 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 139-day season

Sow every 5.7 weeks. Last sowing by Jul 13 to harvest before frost.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.4″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 525 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 1" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 1.3" 0" ❄️ Dormant
May 2.6" 1.9" 0.7" 💧 Light watering
Jun 2.6" 0.9" 1.7" 🚿 Regular watering
Jul 2.6" 1.2" 1.4" 🚿 Regular watering
Aug 2.6" 1.5" 1.1" 💧 Light watering
Sep 2.6" 1.3" 1.3" 🚿 Regular watering
Oct 1.2" 0" ❄️ Dormant
Nov 0.9" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Shoshone 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 ~812 GDD — county provides 1,807 GDD Excellent fit

Basil Planting Timeline — Shoshone County, ID

Basil Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 – Apr 5
Transplant Outdoors May 24 May 24 – Jun 7
Direct Sow May 17 May 17 – Jun 7
Harvest July 19 Jul 19 – Sep 20

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
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.6"/week · 1-2 times/week

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

139 days in Shoshone County

Growing Tips for Basil in Shoshone County

Direct sow Basil outdoors after May 10 in Shoshone 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 Shoshone County, ID?

Shoshone County is in Zone 6b with an average last frost of May 10. Plan your Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Shoshone County, ID?

Shoshone County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 10 and first fall frost is September 26.

🌱

Your Shoshone County Garden Planner — Free

A 24-page printable planner built for Shoshone County (Zone 6b). 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 Shoshone County, ID. 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.