When to plant Calendula in Adams County, CO
In Adams County, plant Calendula in spring between April 6 and April 27, once soil temps hold above 50°F. Adams County's last frost averages May 4, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between and — roughly 50–70 days before the first frost on October 5.
When to Plant Calendula in Adams County, CO
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.
Adams County, Colorado is in USDA Zone 6a. The average last spring frost is May 4 and the first fall frost is October 5, giving you a growing season of approximately 154 days.
At an elevation of 5,827 feet, Adams County receives approximately 23.9 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Calendula during the growing season.
Adams County Soil Profile
Soil Type
Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Calendula Planting Timeline — Adams County, CO
Calendula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 23 | Mar 23 – Apr 6 |
| Transplant Outdoors | May 4 | May 4 – May 18 |
| Direct Sow | April 6 | Apr 6 – Apr 27 |
| Bloom | June 22 | Jun 22 – Sep 21 |
Plant 0.3" deep · 9" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: N/A
🗺️ USDA Zone
Zone 6a
📆 Growing Season
154 days in Adams County
Growing Tips for Adams County
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 Adams County, CO?
Adams County is in Zone 6a with an average last frost of May 4. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.
What planting zone is Adams County, CO?
Adams County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 4 and first fall frost is October 5.
When should I plant Calendula in Adams County, CO?
In Adams County, CO, plant Calendula after the last frost (around May 4) and before the first frost (around October 5). Best results when soil holds above 50°F.
What growing zone is Adams County, CO for Calendula?
Adams County sits in USDA Zone 6a. Calendula grows reliably in zones 2a through 11b, so it's a good fit here.
Can Calendula grow in Adams County's climate?
Yes — Calendula grows well in Adams County's temperate climate. Adams County averages a 154-day frost-free season, with last frost around May 4 and first frost around October 5.
Your Adams County Garden Planner — Free
A 22-page printable planner built for Adams 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.