When to plant Thyme in Broomfield County, CO
Broomfield County sits in cold Zone 6a. Plant Thyme May 21–June 4 for the single annual harvest; the September 26 first frost closes the window.
When to Plant Thyme in Broomfield County, CO
Broomfield County, Colorado gardeners: here's your August plan
Here's what deserves your attention in Broomfield County, Colorado this month. Everything below is tailored to Zone 6a and timed around your local frost dates.
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Bring in the thyme
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
September prep starts now
- First harvests: thyme
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.
Broomfield County, Colorado is in USDA Zone 6a. The average last spring frost is May 14 and the first fall frost is September 26, giving you a growing season of approximately 135 days.
At an elevation of 7,037 feet, Broomfield County receives approximately 13.9 inches of rainfall annually with predominantly loam soil. Summer highs average 87°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.
Broomfield County Soil Profile
Soil Type
Loam
Soil pH
6.2-8.2
Drainage
Well Drained
Thyme Planting Risk Windows
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 Broomfield County
How your county's soil matches Thyme's growing requirements.
Soil pH
Your soil pH (6.2–8.2) overlaps with Thyme's range (6.0–8.0), though not a perfect match.
Soil Texture
The loam soil in Broomfield County is excellent for Thyme — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Thyme.
How to Plant Thyme
Succession Planting Thyme
Sow every 8 weeks. Last sowing by Jun 28 to harvest before frost.
Thyme Water Budget
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 | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 1.1" | 0" | ❄️ Dormant |
| Apr | — | 1.5" | 0" | ❄️ Dormant |
| May | 1.3" | 1.7" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 0.9" | 0.4" | 💧 Light watering |
| Jul | 1.3" | 1.3" | 0" | ✅ Rainfall sufficient |
| Aug | 1.3" | 1.6" | 0" | ✅ Rainfall sufficient |
| Sep | 1.3" | 1.1" | 0.2" | 💧 Light watering |
| Oct | — | 1.2" | 0" | ❄️ Dormant |
| Nov | — | 1" | 0" | ❄️ Dormant |
| Dec | — | 0.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Broomfield 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 Planting Timeline — Broomfield County, CO
Thyme Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 21 | May 21 – Jun 4 |
| Harvest | July 30 | Jul 30 – Oct 1 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| July | Harvest |
| 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: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
135 days in Broomfield County
Growing Tips for Thyme in Broomfield County
Direct sow Thyme outdoors after May 14 in Broomfield 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 →
Thyme in Other Locations
Frequently Asked Questions
When should I plant Thyme in Broomfield County, CO?
Broomfield County is in Zone 6a with an average last frost of May 14. Plan your Thyme planting based on this frost date — see the calendar above for exact timing.
What planting zone is Broomfield County, CO?
Broomfield County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 14 and first fall frost is September 26.
When should I plant Thyme in Broomfield County, CO?
In Broomfield County, CO, plant Thyme after the last frost (around May 14) and before the first frost (around September 26). Best results when soil holds above 50°F.
What growing zone is Broomfield County, CO for Thyme?
Broomfield County sits in USDA Zone 6a. Thyme grows reliably in zones 4a through 9b, so it's a good fit here.
Can Thyme grow in Broomfield County's climate?
Yes — Thyme grows well in Broomfield County's temperate climate. Broomfield County averages a 135-day frost-free season, with last frost around May 14 and first frost around September 26.
Your Broomfield County Garden Planner — Free
A 22-page printable planner built for Broomfield County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.