When to plant Calendula in Houston County, MN
Plant Calendula in Houston County, when soil hits 50°F — usually April 12. Continue planting through May 3 for the spring crop.
When to Plant Calendula in Houston County, MN
Your June game plan for Houston County, Minnesota
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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Time to start calendula inside
These need a head start before your last frost (May 3). Sow into cells now so you're ready to transplant in a few weeks.
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Start harvesting calendula
If you can't use it all right away, check the food-preservation section of your planner.
July will be here before you know it — start on
- 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.
Houston County, Minnesota is in USDA Zone 5a. The average last spring frost is May 3 and the first fall frost is October 6, giving you a growing season of approximately 156 days.
At an elevation of 558 feet, Houston County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Calendula to ensure they mature before fall.
Houston County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7
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 Houston County
How your county's soil matches Calendula's growing requirements.
Soil pH
Your soil pH (6.0–7.0) is within Calendula's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in Houston County is excellent for Calendula — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.3%) — Calendula will thrive.
How to Plant Calendula
Succession Planting Calendula
Sow every 5.7 weeks. Last sowing by Jul 28 to harvest before frost.
Calendula Water Budget
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 | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 3" | 0" | ❄️ Dormant |
| Apr | — | 3.7" | 0" | ❄️ Dormant |
| May | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Houston 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 — Houston County, MN
Calendula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 22 | Mar 22 – Apr 5 |
| Transplant Outdoors | May 3 | May 3 – May 17 |
| Direct Sow | April 12 | Apr 12 – May 3 |
| Bloom | June 21 | Jun 21 – Sep 13 |
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: ideal
🗺️ USDA Zone
Zone 5a
📆 Growing Season
156 days in Houston County
Growing Tips for Calendula in Houston County
Direct sow Calendula outdoors after May 03 in Houston 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 Houston County, MN?
Houston County is in Zone 5a with an average last frost of May 3. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.
What planting zone is Houston County, MN?
Houston County, Minnesota is in USDA Hardiness Zone 5a. The average last spring frost is May 3 and first fall frost is October 6.
When should I plant Calendula in Houston County, MN?
In Houston County, MN, plant Calendula after the last frost (around May 3) and before the first frost (around October 6). Best results when soil holds above 50°F.
What growing zone is Houston County, MN for Calendula?
Houston 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 Houston County's climate?
Yes — Calendula grows well in Houston County's temperate climate. Houston County averages a 156-day frost-free season, with last frost around May 3 and first frost around October 6.
Your Houston County Garden Planner — Free
A 22-page printable planner built for Houston 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.