When to plant Calendula in Bonner County, ID
Plant Calendula in Bonner County, when soil hits 50°F — usually April 7. Continue planting through April 28 for the spring crop.
When to Plant Calendula in Bonner County, ID
Your August planting checklist for Bonner County, Idaho
Welcome to August in Zone 6b. These are the moves that will have the biggest impact on your growing season.
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Collect calendula at their peak
If you can't use it all right away, check the food-preservation section of your planner.
A few tasks this August that'll pay off in September
- 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.
Bonner County, Idaho is in USDA Zone 6b. The average last spring frost is May 5 and the first fall frost is October 3, giving you a growing season of approximately 151 days.
At an elevation of 7,480 feet, Bonner County receives approximately 12.9 inches of rainfall annually with predominantly loam soil. Summer highs average 86°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.
Bonner County Soil Profile
Soil Type
Loam
Soil pH
6.4-8.2
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 Bonner County
How your county's soil matches Calendula's growing requirements.
Soil pH
Your soil pH (6.4–8.2) is more alkaline than Calendula prefers (5.5–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Bonner 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
Succession Planting Calendula
Sow every 5.7 weeks. Last sowing by Jul 25 to harvest before frost.
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 | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 1.1" | 0" | ❄️ Dormant |
| Apr | — | 1.5" | 0" | ❄️ Dormant |
| May | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Jun | 2.2" | 0.9" | 1.3" | 🚿 Regular watering |
| Jul | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| Aug | 2.2" | 1.2" | 1" | 💧 Light watering |
| Sep | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| Oct | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| Nov | — | 0.9" | 0" | ❄️ Dormant |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Bonner 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 — Bonner County, ID
Calendula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 24 | Mar 24 – Apr 7 |
| Transplant Outdoors | May 5 | May 5 – May 19 |
| Direct Sow | April 7 | Apr 7 – Apr 28 |
| Bloom | June 23 | Jun 23 – Sep 29 |
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
0.5"/week · Only during dry spells
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 6b
📆 Growing Season
151 days in Bonner County
Growing Tips for Calendula in Bonner County
Direct sow Calendula outdoors after May 05 in Bonner 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.
Bonner County receives only 13" 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 Bonner County, ID?
Bonner County is in Zone 6b with an average last frost of May 5. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.
What planting zone is Bonner County, ID?
Bonner County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 5 and first fall frost is October 3.
When should I plant Calendula in Bonner County, ID?
In Bonner County, ID, plant Calendula after the last frost (around May 5) and before the first frost (around October 3). Best results when soil holds above 50°F.
What growing zone is Bonner County, ID for Calendula?
Bonner County sits in USDA Zone 6b. Calendula grows reliably in zones 2a through 11b, so it's a good fit here.
Can Calendula grow in Bonner County's climate?
Yes — Calendula grows well in Bonner County's temperate climate. Bonner County averages a 151-day frost-free season, with last frost around May 5 and first frost around October 3.
Your Bonner County Garden Planner — Free
A 22-page printable planner built for Bonner County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.