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When to Plant Lemon Thyme in San Miguel County, CO

San Miguel County, Colorado Zone 5b May

Your May gardening checklist

Welcome to May in Zone 5b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 31
Avg. first frost September 21
Soil temp (4") 34°F
Watering High
Pest pressure Low
Daylight 14.1 hrs
Looking ahead to June
  • Transplants going out: lemon thyme

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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.

San Miguel County, Colorado is in USDA Zone 5b. The average last spring frost is May 31 and the first fall frost is September 21, giving you a growing season of approximately 113 days.

At an elevation of 8,402 feet, San Miguel County receives approximately 21.6 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Lemon Thyme during the growing season.

San Miguel County, CO (Zone 5b) Short season
113 days
Last Spring Frost May 31
113 growing days
First Fall Frost September 21

San Miguel County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 20 🍅 Harvest: Jul 29 – Sep 30
Recommended (50%) ✗ May not fit
Transplant: Jun 7 🍅 Harvest: Aug 16 – Oct 18
Safe Start (90%) ✗ May not fit
Transplant: Jul 4 🍅 Harvest: Sep 12 – Nov 14

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 San Miguel County

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

Soil pH

Your soil pH (6.8–7.6) is within Lemon Thyme's preferred range (6.0–8.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Lemon Thyme.

How to Plant Lemon Thyme

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

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Lemon Thyme

Lemon Thyme needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Lemon Thyme Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 2.2" 2.6" 0" ✅ Rainfall sufficient
Jun 2.2" 1.4" 0.8" 💧 Light watering
Jul 2.2" 1.7" 0.5" 💧 Light watering
Aug 2.2" 2.5" 0" ✅ Rainfall sufficient
Sep 2.2" 1.5" 0.7" 💧 Light watering
Oct 1.7" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

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

Lemon 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.

Lemon Thyme needs ~1,100 GDD — county provides 1,553 GDD Excellent fit

Lemon Thyme Planting Timeline — San Miguel County, CO

Lemon Thyme Planting Calendar

Activity When Date Range
Transplant Outdoors June 7 Jun 7 – Jun 21
Harvest August 16 Aug 16 – Oct 18

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

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–8 · Your soil: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

113 days in San Miguel County

Growing Tips for Lemon Thyme in San Miguel County

Direct sow Lemon Thyme outdoors after May 31 in San Miguel County when soil has warmed and frost danger has passed.

San Miguel County receives only 22" of rain annually. Lemon Thyme needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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 San Miguel County, CO?

San Miguel County is in Zone 5b with an average last frost of May 31. Plan your Lemon Thyme planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Miguel County, CO?

San Miguel County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 31 and first fall frost is September 21.

🌱

Your San Miguel County Garden Planner — Free

A 24-page printable planner built for San Miguel County (Zone 5b). 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 San Miguel County, CO. 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.