When to plant Marigolds in Brown County, IL
In Brown County, plant Marigolds in spring between April 24 and May 15, once soil temps hold above 50°F. Brown County's last frost averages April 17, 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 16.
When to Plant Marigolds in Brown County, IL
Your June game plan for Brown County, Illinois
June is a pivotal month for Brown County, Illinois gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Basket week: marigolds
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
A few tasks this June that'll pay off in July
- First harvests: marigolds
Marigolds (Tagetes patula) are warm-season annuals beloved for their cheerful orange, yellow, and red blooms — and for their well-documented ability to repel pest nematodes in vegetable beds. Easy from seed, drought-tolerant once established, and bloom from early summer until the first hard frost.
Brown County, Illinois is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 16, giving you a growing season of approximately 182 days.
At an elevation of 868 feet, Brown County receives approximately 36.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Marigolds during the growing season.
Brown County Soil Profile
Soil Type
Silt Loam
Soil pH
6.3-6.8
Drainage
Well Drained
Marigolds 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 Brown County
How your county's soil matches Marigolds's growing requirements.
Soil pH
Your soil pH (6.3–6.8) is within Marigolds's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in Brown County is excellent for Marigolds — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.2%) — Marigolds will thrive.
How to Plant Marigolds
Succession Planting Marigolds
Sow every 5.7 weeks. Last sowing by Aug 07 to harvest before frost.
Marigolds Water Budget
Monthly Watering Guide for Marigolds
Marigolds 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 | Marigolds Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Brown County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Marigolds 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.
Marigolds Planting Timeline — Brown County, IL
Marigolds Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 6 | Mar 6 – Mar 20 |
| Transplant Outdoors | April 24 | Apr 24 – May 8 |
| Direct Sow | April 24 | Apr 24 – May 15 |
| Bloom | June 19 | Jun 19 – Sep 18 |
Plant 0.3" deep · 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors 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 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 6a
📆 Growing Season
182 days in Brown County
Growing Tips for Marigolds in Brown County
Direct sow Marigolds outdoors after April 17 in Brown County when soil has warmed and frost danger has passed.
Common pests for Marigolds in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct-sow after last frost or start indoors 4-6 weeks earlier. Deadhead spent blooms to keep new flowers coming. French marigolds (T. patula) are the most reliable nematode repellents — plant a band around vegetable beds. Tolerate poor soil but bloom best with monthly compost.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Very easy to save. Seeds are the long, thin, dark pieces inside the dried flower head.
Marigolds in Other Locations
Frequently Asked Questions
When should I plant Marigolds in Brown County, IL?
Brown County is in Zone 6a with an average last frost of April 17. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.
What planting zone is Brown County, IL?
Brown County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 16.
When should I plant Marigolds in Brown County, IL?
In Brown County, IL, plant Marigolds after the last frost (around April 17) and before the first frost (around October 16). Best results when soil holds above 50°F.
What growing zone is Brown County, IL for Marigolds?
Brown County sits in USDA Zone 6a. Marigolds grows reliably in zones 2a through 11b, so it's a good fit here.
Can Marigolds grow in Brown County's climate?
Yes — Marigolds grows well in Brown County's temperate climate. Brown County averages a 182-day frost-free season, with last frost around April 17 and first frost around October 16.
Your Brown County Garden Planner — Free
A 22-page printable planner built for Brown 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.