When to plant Calendula in Blue Earth County, MN
Blue Earth County's spring Calendula window runs April 8 through April 29. time plantings around the expected last-frost window for best survival.
When to Plant Calendula in Blue Earth County, MN
What to do in June
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.
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Fire up the seed-starting tray: calendula
Starting these indoors now means sturdy transplants ready the moment your soil warms up.
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It's harvest week for calendula
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Looking ahead to July
- 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.
Blue Earth County, Minnesota is in USDA Zone 5a. The average last spring frost is April 29 and the first fall frost is October 4, giving you a growing season of approximately 158 days.
At an elevation of 646 feet, Blue Earth County receives approximately 40.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Calendula to ensure they mature before fall.
Blue Earth County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.8
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 Blue Earth County
How your county's soil matches Calendula's growing requirements.
Soil pH
Your soil pH (5.9–6.8) is within Calendula's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in Blue Earth County is excellent for Calendula — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (4.0%). Annual compost additions will help Calendula.
How to Plant Calendula
Succession Planting Calendula
Sow every 5.7 weeks. Last sowing by Jul 26 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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 3.1" | 0" | ❄️ Dormant |
| Apr | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 5.1" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 2.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Blue Earth 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 — Blue Earth County, MN
Calendula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 18 | Mar 18 – Apr 1 |
| Transplant Outdoors | April 29 | Apr 29 – May 13 |
| Direct Sow | April 8 | Apr 8 – Apr 29 |
| Bloom | June 17 | Jun 17 – Sep 9 |
Plant 0.3" deep · 9" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors 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 · Natural rainfall sufficient
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: ideal
🗺️ USDA Zone
Zone 5a
📆 Growing Season
158 days in Blue Earth County
Growing Tips for Calendula in Blue Earth County
Direct sow Calendula outdoors after April 29 in Blue Earth 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 Blue Earth County, MN?
Blue Earth County is in Zone 5a with an average last frost of April 29. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.
What planting zone is Blue Earth County, MN?
Blue Earth County, Minnesota is in USDA Hardiness Zone 5a. The average last spring frost is April 29 and first fall frost is October 4.
When should I plant Calendula in Blue Earth County, MN?
In Blue Earth County, MN, plant Calendula after the last frost (around April 29) and before the first frost (around October 4). Best results when soil holds above 50°F.
What growing zone is Blue Earth County, MN for Calendula?
Blue Earth County sits in USDA Zone 5a. Calendula grows reliably in zones 2a through 11b, so it's a good fit here.
Can Calendula grow in Blue Earth County's climate?
Yes — Calendula grows well in Blue Earth County's temperate climate. Blue Earth County averages a 158-day frost-free season, with last frost around April 29 and first frost around October 4.
Your Blue Earth County Garden Planner — Free
A 22-page printable planner built for Blue Earth County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.