When to plant Calendula in Mesa County, CO
For Calendula in Mesa County, the safe spring window opens around March 27 and closes around April 17. Last expected frost is May 1, first fall frost October 9, giving a 161-day growing season. A second sowing from August 14 to August 28 extends the harvest into fall.
When to Plant Calendula in Mesa County, CO
Your July game plan for Mesa County, Colorado
July is a pivotal month for Mesa County, Colorado gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Pick calendula
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Looking ahead to August
- First harvests: calendula
- Fall sowing: calendula
Calendula (Calendula officinalis) is a cheerful, edible-flowered cool-season annual valued by herbalists, chefs, and gardeners alike. Its golden-orange petals are used in salves, teas, and as a saffron substitute. Hardy enough to tolerate light frosts, it blooms prolifically in spring and fall, taking a pause during the hottest weeks of summer.
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 Calendula during the growing season.
Mesa County Soil Profile
Soil Type
Loam
Soil pH
6.7-8.1
Drainage
Well Drained
Calendula 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 Calendula's growing requirements.
Soil pH
Your soil pH (6.7–8.1) is more alkaline than Calendula prefers (5.5–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Mesa County is excellent for Calendula — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Calendula.
How to Plant Calendula
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Calendula
Sow every 5.7 weeks. Last sowing by Jul 31 to harvest before frost.
For a dedicated fall crop, sow by Aug 14.
Calendula Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Calendula
Calendula 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 | Calendula 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 | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 1.8" | 0.4" | 💧 Light watering |
| Jul | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Aug | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Oct | 2.2" | 1.8" | 0.4" | 💧 Light watering |
| 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.
Calendula 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.
Calendula Planting Timeline — Mesa County, CO
Calendula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 20 | Mar 20 – Apr 3 |
| Transplant Outdoors | May 1 | May 1 – May 15 |
| Direct Sow | March 27 | Mar 27 – Apr 17 |
| Bloom | June 19 | Jun 19 – Oct 2 |
| Fall Sowing | August 14 | Aug 14 – Aug 28 |
Plant 0.3" deep · 9" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors |
| June | Bloom |
| July | Bloom |
| August | Fall Sowing Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 7a
📆 Growing Season
161 days in Mesa County
Growing Tips for Calendula in Mesa County
Direct sow Calendula outdoors after May 01 in Mesa County when soil has warmed and frost danger has passed.
Common pests for Calendula in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
Mesa County receives only 23" of rain annually. Calendula needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Direct-sow in early spring as soon as soil can be worked — seeds germinate in cool soil (50-65°F). In zones 7+, also sow in fall for winter/spring bloom. Deadhead consistently to extend bloom. Plants self-seed readily; save a few spent heads and allow them to drop. Harvest petals when flowers are fully open for best flavor and medicinal value.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Calendula in Other Locations
Frequently Asked Questions
When should I plant Calendula in Mesa County, CO?
Mesa County is in Zone 7a with an average last frost of May 1. Plan your Calendula 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.
When should I plant Calendula in Mesa County, CO?
In Mesa County, CO, plant Calendula after the last frost (around May 1) and before the first frost (around October 9). Best results when soil holds above 50°F.
What growing zone is Mesa County, CO for Calendula?
Mesa County sits in USDA Zone 7a. Calendula grows reliably in zones 2a through 11b, so it's a good fit here.
Can Calendula grow in Mesa County's climate?
Yes — Calendula grows well in Mesa County's temperate climate. Mesa County averages a 161-day frost-free season, with last frost around May 1 and first frost around October 9.
Your Mesa County Garden Planner — Free
A 22-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.