When to plant Calendula in Butte County, CA
Plant Calendula in Butte County from February 16 to March 9 in spring. Butte County sits in USDA Zone 9b, with last frost around April 20 and first frost on November 10. A second sowing from August 18 to September 1 extends the harvest into fall.
When to Plant Calendula in Butte County, CA
Butte County, California gardeners: here's your June plan
If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.
-
Bring in the calendula
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
Before July arrives, get these ready
- First harvests: 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.
Butte County, California is in USDA Zone 9b. The average last spring frost is April 20 and the first fall frost is November 10, giving you a growing season of approximately 204 days.
At an elevation of 144 feet, Butte County receives approximately 44.8 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Calendula during the growing season.
Butte County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.7
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 Butte County
How your county's soil matches Calendula's growing requirements.
Soil pH
Your soil pH (6.8–7.7) is more alkaline than Calendula prefers (5.5–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Butte County is excellent for Calendula — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Calendula.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Calendula.
How to Plant Calendula
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Calendula
Sow every 5.7 weeks. Last sowing by Sep 01 to harvest before frost.
For a dedicated fall crop, sow by Aug 18.
Calendula Water Budget
Water stress score is 8/10 — 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 | — | 9.7" | 0" | ❄️ Dormant |
| Feb | — | 9.9" | 0" | ❄️ Dormant |
| Mar | — | 6.9" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| Jun | 2.2" | 0.2" | 2" | 🚿 Regular watering |
| Jul | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Aug | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Sep | 2.2" | 0.4" | 1.8" | 🚿 Regular watering |
| Oct | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Nov | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Dec | — | 7.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Butte 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 — Butte County, CA
Calendula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | March 16 | Mar 16 – Mar 30 |
| Direct Sow | February 16 | Feb 16 – Mar 9 |
| Bloom | April 27 | Apr 27 – Aug 17 |
| Fall Sowing | August 18 | Aug 18 – Sep 1 |
Plant 0.3" deep · 9" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Fall Sowing Bloom |
| September | Fall Sowing |
| October | — |
| 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 9b
📆 Growing Season
204 days in Butte County
Growing Tips for Calendula in Butte County
Direct sow Calendula outdoors after April 20 in Butte 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.
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 Butte County, CA?
Butte County is in Zone 9b with an average last frost of April 20. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.
What planting zone is Butte County, CA?
Butte County, California is in USDA Hardiness Zone 9b. The average last spring frost is April 20 and first fall frost is November 10.
When should I plant Calendula in Butte County, CA?
In Butte County, CA, plant Calendula after the last frost (around April 20) and before the first frost (around November 10). Best results when soil holds above 50°F.
What growing zone is Butte County, CA for Calendula?
Butte County sits in USDA Zone 9b. Calendula grows reliably in zones 2a through 11b, so it's a good fit here.
Can Calendula grow in Butte County's climate?
Yes — Calendula grows well in Butte County's temperate climate. Butte County averages a 204-day frost-free season, with last frost around April 20 and first frost around November 10.
Your Butte County Garden Planner — Free
A 22-page printable planner built for Butte County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.