When to plant Calendula in Forsyth, IL
In Forsyth, plant Calendula in spring between March 16 and April 6, once soil temps hold above 50°F. Forsyth's last frost averages April 13, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between and — roughly 50–70 days before the first frost on October 19.
When to Plant Calendula in Forsyth, IL
Macon County, Illinois gardeners: here's your July plan
Each item below is timed to Macon County, Illinois's frost dates and soil temperatures. Skip nothing, stress about nothing.
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It's harvest week for calendula
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
Coming up in August — 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.
Forsyth, Illinois is in USDA Zone 6a. The average last spring frost is April 13 and the first fall frost is October 19, giving you a growing season of approximately 189 days.
At an elevation of 1,064 feet, Macon County receives approximately 31.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Calendula during the growing season.
Forsyth Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.1
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 Forsyth
How your county's soil matches Calendula's growing requirements.
Soil pH
Your soil pH (6.0–7.1) overlaps with Calendula's range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Macon 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 Aug 10 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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.1" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Macon 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 — Forsyth, IL
Calendula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 2 | Mar 2 – Mar 16 |
| Transplant Outdoors | April 13 | Apr 13 – Apr 27 |
| Direct Sow | March 16 | Mar 16 – Apr 6 |
| Bloom | June 1 | Jun 1 – Aug 31 |
Plant 0.3" deep · 9" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | — |
| 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: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
189 days in Macon County
Growing Tips for Calendula in Forsyth
Direct sow Calendula outdoors after April 13 in Macon 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
When should I plant Calendula in Forsyth, IL?
In Forsyth, IL, plant Calendula after the last frost (around April 13) and before the first frost (around October 19). Best results when soil holds above 50°F.
What growing zone is Forsyth, IL for Calendula?
Forsyth sits in USDA Zone 6a. Calendula grows reliably in zones 2a through 11b, so it's a good fit here.
Can Calendula grow in Forsyth's climate?
Yes — Calendula grows well in Forsyth's temperate climate. Forsyth averages a 189-day frost-free season, with last frost around April 13 and first frost around October 19.
Your Macon County Garden Planner — Free
A 22-page printable planner built for Macon County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.