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When to plant Lemon Thyme in Flathead County, MT

Plant Lemon Thyme in Flathead County, between June 10 and June 24 — the only viable window. Zone 5a's short season (99 frost-free days) rules out a fall crop.

When to Plant Lemon Thyme in Flathead County, MT

Lemon thyme is a low-growing perennial herb with tiny, citrus-scented leaves. It combines the savory quality of thyme with a bright lemon flavor, excellent with fish and poultry.

Flathead County, Montana is in USDA Zone 5a. The average last spring frost is June 3 and the first fall frost is September 10, giving you a growing season of approximately 99 days.

At an elevation of 6,233 feet, Flathead County receives approximately 20.7 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Lemon Thyme during the growing season.

Flathead County, MT (Zone 5a) Very short season
99 days
Last Spring Frost June 3
99 growing days
First Fall Frost September 10

Flathead County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.4

Drainage

Well Drained

Monthly Watering Guide for Lemon Thyme

Lemon Thyme needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Lemon Thyme Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 2.7" 0" ❄️ Dormant
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 2.1" 2.2" 🚿 Regular watering
Sep 4.3" 1.5" 2.8" 🚿 Regular watering
Oct 1.9" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

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

Lemon Thyme Planting Timeline — Flathead County, MT

Lemon Thyme Planting Calendar

Activity When Date Range
Transplant Outdoors June 10 Jun 10 – Jun 24
Harvest August 19 Aug 19 – Oct 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–8 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

99 days in Flathead County

Growing Tips for Flathead County

Start from cuttings or divisions. Plant in well-drained soil. Trim back after flowering. Use as a fragrant ground cover or edging plant along garden paths.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lemon Thyme in Flathead County, MT?

Flathead County is in Zone 5a with an average last frost of June 3. Plan your Lemon Thyme planting based on this frost date — see the calendar above for exact timing.

What planting zone is Flathead County, MT?

Flathead County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is June 3 and first fall frost is September 10.

When should I plant Lemon Thyme in Flathead County, MT?

In Flathead County, MT, plant Lemon Thyme after the last frost (around June 3) and before the first frost (around September 10). Best results when soil holds above 50°F.

What growing zone is Flathead County, MT for Lemon Thyme?

Flathead County sits in USDA Zone 5a. Lemon Thyme grows reliably in zones 5a through 9b, so it's a good fit here.

Can Lemon Thyme grow in Flathead County's climate?

Yes — Lemon Thyme grows well in Flathead County's temperate climate. Flathead County averages a 99-day frost-free season, with last frost around June 3 and first frost around September 10.

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Your Flathead County Garden Planner — Free

A 22-page printable planner built for Flathead 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.

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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 Flathead County, MT. Local conditions may vary. Last updated: July 2026.

Sources & credits

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