When to plant Calendula in Imperial County County,
Calendula planted in Imperial County County between November 20 and December 11 matures in 70 days — well before the December 20 first frost. A second sowing from September 13 to September 27 extends the harvest into fall.
When to Plant Calendula in Imperial County, CA
Your June game plan for Imperial County, California
June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Imperial County, California.
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Survive, don't thrive
June-August is endurance gardening. Keep okra, peppers, sweet potatoes, and southern peas alive. Harvest everything daily before the heat damages produce on the vine.
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Start fall tomato seeds indoors
Yes, indoors — under lights or in AC. They'll be ready to transplant in August when temperatures briefly moderate.
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Add compost to empty beds
Empty beds get a thick layer of compost + mulch to suppress weeds and feed the soil for fall planting.
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.
Imperial County, California is in USDA Zone 10a. The average last spring frost is January 29 and the first fall frost is December 20, giving you a growing season of approximately 325 days.
At an elevation of 181 feet, Imperial County receives approximately 16.8 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Calendula during the growing season. With low rainfall, drip irrigation is essential for growing Calendula successfully. Mulch heavily to conserve soil moisture.
Imperial County Soil Profile
Soil Type
Loam
Soil pH
5.7-7.3
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 Imperial County
How your county's soil matches Calendula's growing requirements.
Soil pH
Your soil pH (5.7–7.3) overlaps with Calendula's range (5.5–7.0), though not a perfect match.
Soil Texture
The loam soil in Imperial County is excellent for Calendula — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help Calendula.
How to Plant Calendula
Fall planting: Sow 14 weeks before your first frost date for a fall harvest.
Succession Planting Calendula
Sow every 5.7 weeks. Last sowing by Oct 11 to harvest before frost.
For a dedicated fall crop, sow by Sep 13.
Calendula Water Budget
Water stress score is 10/10 — 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 | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Feb | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 3.1" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 1.4" | 0.8" | 💧 Light watering |
| May | 2.2" | 0.4" | 1.8" | 🚿 Regular watering |
| Jun | 2.2" | 0.1" | 2.1" | 🚿 Regular watering |
| Jul | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Aug | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Sep | 2.2" | 0.2" | 2" | 🚿 Regular watering |
| Oct | 2.2" | 0.6" | 1.6" | 🚿 Regular watering |
| Nov | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Dec | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Jan–Dec in Imperial 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 — Imperial County, CA
Calendula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | December 18 | Dec 18 – Jan 1 |
| Direct Sow | November 20 | Nov 20 – Dec 11 |
| Bloom | January 29 | Jan 29 – May 7 |
| Fall Sowing | September 13 | Sep 13 – Sep 27 |
Plant 0.3" deep · 9" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors Bloom |
| February | Bloom |
| March | Bloom |
| April | Bloom |
| May | Bloom |
| June | — |
| July | — |
| August | — |
| September | Fall Sowing |
| October | — |
| November | Direct Sow |
| December | Transplant Outdoors Direct Sow |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · 1-2 times/week
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 10a
📆 Growing Season
325 days in Imperial County
Growing Tips for Calendula in Imperial County
Direct sow Calendula outdoors after January 29 in Imperial 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.
Imperial County receives only 17" 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 Imperial County, CA?
Imperial County is in Zone 10a with an average last frost of January 29. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.
What planting zone is Imperial County, CA?
Imperial County, California is in USDA Hardiness Zone 10a. The average last spring frost is January 29 and first fall frost is December 20.
When should I plant Calendula in Imperial County County, ?
In Imperial County County, , plant Calendula after the last frost (around January 29) and before the first frost (around December 20). Best results when soil holds above 50°F.
What growing zone is Imperial County County, for Calendula?
Imperial County County sits in USDA Zone 10a. Calendula grows reliably in zones 2a through 11b, so it's a good fit here.
Can Calendula grow in Imperial County County's climate?
Yes — Calendula grows well in Imperial County County's temperate climate. Imperial County County averages a 326-day frost-free season, with last frost around January 29 and first frost around December 20.
Your Imperial County Garden Planner — Free
A 22-page printable planner built for Imperial County (Zone 10a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.