When to Plant Rosemary in Mesa County, CO
Mesa County, Colorado gardeners: here's your May plan
Each item below is timed to Mesa County, Colorado's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Get rosemary in the ground
Frost risk is low now in Mesa County, Colorado. If you've been covering beds overnight, you can stop.
Rosemary is an aromatic evergreen shrub with needle-like leaves and a piney, citrus flavor. It is a Mediterranean herb that thrives in warm, dry conditions.
Mesa County, Colorado is in USDA Zone 7a. The average last spring frost is May 1 and the first fall frost is October 9, giving you a growing season of approximately 161 days.
At an elevation of 6,091 feet, Mesa County receives approximately 23.3 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Rosemary during the growing season.
Mesa County Soil Profile
Soil Type
Loam
Soil pH
6.7-8.1
Drainage
Well Drained
Plant 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 Mesa County
How your county's soil matches Rosemary's growing requirements.
Soil pH
Your soil pH (6.7–8.1) overlaps with Rosemary's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Mesa County is excellent for Rosemary — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Rosemary.
How to Plant Rosemary
Succession Planting Rosemary
Sow every 9.1 weeks. Last sowing by Apr 12 to harvest before frost.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Rosemary
Rosemary 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 | Rosemary Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | — | 2.5" | 0" | ❄️ Dormant |
| May | 1.3" | 2.6" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 1.8" | 0" | ✅ Rainfall sufficient |
| Jul | 1.3" | 2.1" | 0" | ✅ Rainfall sufficient |
| Aug | 1.3" | 2.5" | 0" | ✅ Rainfall sufficient |
| Sep | 1.3" | 1.9" | 0" | ✅ Rainfall sufficient |
| Oct | 1.3" | 1.8" | 0" | ✅ Rainfall sufficient |
| Nov | — | 1.7" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Mesa County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Rosemary 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.
Rosemary Planting Timeline — Mesa County, CO
Rosemary Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 8 | May 8 – May 22 |
| Harvest | July 31 | Jul 31 – Dec 18 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | Harvest |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.3"/week · Natural rainfall sufficient
📅 Days to Maturity
80–180 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
161 days in Mesa County
Growing Tips for Rosemary in Mesa County
Direct sow Rosemary outdoors after May 01 in Mesa County when soil has warmed and frost danger has passed.
Your 161.0-day growing season in Mesa County is tight for Rosemary (80.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.
General growing tips
Grow in well-drained soil and avoid overwatering. In cold climates, grow in containers and bring indoors for winter. Propagate from stem cuttings for faster results than seed.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Rosemary in Other Locations
Frequently Asked Questions
When should I plant Rosemary in Mesa County, CO?
Mesa County is in Zone 7a with an average last frost of May 1. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.
What planting zone is Mesa County, CO?
Mesa County, Colorado is in USDA Hardiness Zone 7a. The average last spring frost is May 1 and first fall frost is October 9.
Your Mesa County Garden Planner — Free
A 24-page printable planner built for Mesa County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.