When to Plant Calendula in Cass County, ND
June in the garden — Cass County, North Dakota
We've pulled the most time-sensitive tasks for Cass County, North Dakota this June and put them front and centre. Tackle them in order.
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Start calendula under lights
These need a head start before your last frost (May 11). Sow into cells now so you're ready to transplant in a few weeks.
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Harvest calendula as they ripen
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
Coming up in July — start thinking about
- 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.
Cass County, North Dakota is in USDA Zone 4a. The average last spring frost is May 11 and the first fall frost is October 2, giving you a growing season of approximately 144 days.
At an elevation of 839 feet, Cass County receives approximately 33.1 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Calendula to ensure they mature before fall.
Cass County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.6
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 Cass County
How your county's soil matches Calendula's growing requirements.
Soil pH
Your soil pH (6.5–7.6) is more alkaline than Calendula prefers (5.5–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Cass County is excellent for Calendula — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.4%). Annual compost additions will help Calendula.
How to Plant Calendula
Succession Planting Calendula
Sow every 5.7 weeks. Last sowing by Jul 24 to harvest before frost.
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 | — | 0.8" | 0" | ❄️ Dormant |
| Feb | — | 1" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | — | 3.6" | 0" | ❄️ Dormant |
| May | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 5.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 1.1" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Cass 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 — Cass County, ND
Calendula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 23 | Mar 23 – Apr 6 |
| Transplant Outdoors | May 11 | May 11 – May 25 |
| Direct Sow | April 27 | Apr 27 – May 18 |
| Bloom | June 29 | Jun 29 – Sep 14 |
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 Direct Sow |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| 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 4a
📆 Growing Season
144 days in Cass County
Growing Tips for Calendula in Cass County
Direct sow Calendula outdoors after May 11 in Cass 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 Cass County, ND?
Cass County is in Zone 4a with an average last frost of May 11. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.
What planting zone is Cass County, ND?
Cass County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 11 and first fall frost is October 2.
Your Cass County Garden Planner — Free
A 22-page printable planner built for Cass County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.