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When to plant Thyme in Lewis County, ID

Plant Thyme in Lewis County during the brief May 27–June 10 window. With 126 frost-free days, fall plantings can't mature before September 23.

When to Plant Thyme in Lewis County, ID

Thyme
Lewis County, Idaho Zone 6b June

Your June gardening checklist

Your Lewis County, Idaho garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost May 20
Avg. first frost September 23
Soil temp (4") 57°F
Watering Critical
Pest pressure High
Daylight 15.6 hrs

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Thyme is a low-growing perennial herb with tiny, aromatic leaves and a warm, earthy flavor. It is one of the most versatile culinary and medicinal herbs.

Lewis County, Idaho is in USDA Zone 6b. The average last spring frost is May 20 and the first fall frost is September 23, giving you a growing season of approximately 126 days.

At an elevation of 4,861 feet, Lewis County receives approximately 13.5 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Thyme during the growing season. With low rainfall, drip irrigation is essential for growing Thyme successfully. Mulch heavily to conserve soil moisture.

Lewis County, ID (Zone 6b) Short season
126 days
Last Spring Frost May 20
126 growing days
First Fall Frost September 23

Lewis County Soil Profile

Soil Type

Loam

Soil pH

6.7-8

Drainage

Well Drained

Thyme Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 19 🍅 Harvest: Jul 28 – Sep 29
Recommended (50%) ✗ May not fit
Transplant: May 27 🍅 Harvest: Aug 5 – Oct 7
Safe Start (90%) ✗ May not fit
Transplant: Jun 17 🍅 Harvest: Aug 26 – Oct 28

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 Lewis County

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

Soil pH

Your soil pH (6.7–8.0) is within Thyme's preferred range (6.0–8.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Thyme.

How to Plant Thyme

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

Succession Planting Thyme

2
successive plantings in your 126-day season

Sow every 8 weeks. Last sowing by Jun 25 to harvest before frost.

Thyme Water Budget

Plant needs
0.3″/week
Rainfall provides
0.5″/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 Thyme

Thyme needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.

Month Thyme Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.1" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 1.3" 1.7" 0" ✅ Rainfall sufficient
Jun 1.3" 0.8" 0.5" 💧 Light watering
Jul 1.3" 1.2" 0.1" 💧 Light watering
Aug 1.3" 1.4" 0" ✅ Rainfall sufficient
Sep 1.3" 1.2" 0.1" 💧 Light watering
Oct 1.3" 0" ❄️ Dormant
Nov 0.8" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Lewis County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Thyme 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.

Thyme needs ~1,400 GDD — county provides 2,205 GDD Excellent fit

Thyme Planting Timeline — Lewis County, ID

Thyme Planting Calendar

Activity When Date Range
Transplant Outdoors May 27 May 27 – Jun 10
Harvest August 5 Aug 5 – Oct 7

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.3"/week · Natural rainfall sufficient

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–8 · Your soil: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

126 days in Lewis County

Growing Tips for Thyme in Lewis County

Direct sow Thyme outdoors after May 20 in Lewis County when soil has warmed and frost danger has passed.

General growing tips

Start from seed, cuttings, or divisions. Plant in well-drained, lean soil. Prune lightly after flowering. Replace plants every 3-4 years when they become woody.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Thyme in Lewis County, ID?

Lewis County is in Zone 6b with an average last frost of May 20. Plan your Thyme planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lewis County, ID?

Lewis County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 20 and first fall frost is September 23.

When should I plant Thyme in Lewis County, ID?

In Lewis County, ID, plant Thyme after the last frost (around May 20) and before the first frost (around September 23). Best results when soil holds above 50°F.

What growing zone is Lewis County, ID for Thyme?

Lewis County sits in USDA Zone 6b. Thyme grows reliably in zones 4a through 9b, so it's a good fit here.

Can Thyme grow in Lewis County's climate?

Yes — Thyme grows well in Lewis County's temperate climate. Lewis County averages a 126-day frost-free season, with last frost around May 20 and first frost around September 23.

🌱

Your Lewis County Garden Planner — Free

A 22-page printable planner built for Lewis 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 Lewis County, ID. 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.