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When to plant Coreopsis in Monroe County County,

Monroe County County gardeners should plant Coreopsis between April 14 and May 5 in spring. With Monroe County County's Zone 7a climate (last frost April 14), Coreopsis needs 80 days to mature — plant by August 5 for a full harvest.

When to Plant Coreopsis in Monroe County, IL

Monroe County, Illinois Zone 7a June

June to-do list for Monroe County, Illinois

Your Monroe County, Illinois garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost April 14
Avg. first frost October 24
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Start coreopsis indoors

    These need a head start before your last frost (April 14). Sow into cells now so you're ready to transplant in a few weeks.

  2. Bring in the coreopsis

    If you can't use it all right away, check the food-preservation section of your planner.

Coming up in July — start thinking about
  • First harvests: coreopsis

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Coreopsis (Tickseed) is a cheerful, long-blooming native perennial that produces a continuous flush of bright yellow, gold, or bi-colored daisy-like flowers from early summer well into fall. One of the most reliable cut-and-come-again bloomers in the perennial garden, it thrives in hot, dry, sunny conditions and poor soil where many competitors struggle. An invaluable nectar source for native bees and butterflies, and a butterfly host plant for several species.

Monroe County, Illinois is in USDA Zone 7a. The average last spring frost is April 14 and the first fall frost is October 24, giving you a growing season of approximately 193 days.

At an elevation of 1,278 feet, Monroe County receives approximately 34.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Coreopsis during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Monroe County, IL (Zone 7a) Moderate season
193 days
Last Spring Frost April 14
193 growing days
First Fall Frost October 24
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Monroe County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 2 Transplant: Apr 13 🌸 Bloom: Jun 15 – Oct 26
Recommended (50%) ✗ May not fit
Start indoors: Feb 10 Transplant: Apr 21 🌸 Bloom: Jun 23 – Nov 3
Safe Start (90%) ✗ May not fit
Start indoors: Feb 21 Transplant: May 2 🌸 Bloom: Jul 4 – Nov 14

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 Monroe County

How your county's soil matches Coreopsis's growing requirements.

Soil pH

Your soil pH (5.7–6.8) is within Coreopsis's preferred range (5.5–7.5).

Soil Texture

The silt loam soil in Monroe County is excellent for Coreopsis — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.2%) — Coreopsis will thrive.

How to Plant Coreopsis

0.1"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Coreopsis

3
successive plantings in your 193-day season

Sow every 6.9 weeks. Last sowing by Aug 05 to harvest before frost.

Coreopsis Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Coreopsis

Coreopsis 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 Coreopsis Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 2.2" 3.1" 0" ✅ Rainfall sufficient
May 2.2" 3.6" 0" ✅ Rainfall sufficient
Jun 2.2" 4.1" 0" ✅ Rainfall sufficient
Jul 2.2" 4.1" 0" ✅ Rainfall sufficient
Aug 2.2" 4" 0" ✅ Rainfall sufficient
Sep 2.2" 2.9" 0" ✅ Rainfall sufficient
Oct 2.2" 2.7" 0" ✅ Rainfall sufficient
Nov 2.4" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Monroe County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Coreopsis 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.

Coreopsis needs ~1,120 GDD — county provides 3,088 GDD Excellent fit

Coreopsis Planting Timeline — Monroe County, IL

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors February 10 Feb 10 – Feb 24
Transplant Outdoors April 21 Apr 21 – May 5
Direct Sow April 14 Apr 14 – May 5
Bloom June 23 Jun 23 – Nov 3

Plant 0.1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November Bloom
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

193 days in Monroe County

Growing Tips for Coreopsis in Monroe County

Direct sow Coreopsis outdoors after April 14 in Monroe County when soil has warmed and frost danger has passed.

Common pests for Coreopsis in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 8–10 weeks before last frost or direct sow after last frost. Seeds germinate easily without stratification. Thrives in poor to average, well-drained soil — rich soil promotes foliage over flowers. Drought tolerant once established; overwatering is the most common mistake. Deadhead spent blooms to maintain continuous flowering through the season. Shear plants by one-third in midsummer for a fresh flush of late-season blooms. Year 2+ plants bloom most heavily. Divide every 2–3 years in early spring to rejuvenate crowded clumps.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Coreopsis in Monroe County, IL?

Monroe County is in Zone 7a with an average last frost of April 14. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.

What planting zone is Monroe County, IL?

Monroe County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 14 and first fall frost is October 24.

When should I plant Coreopsis in Monroe County County, ?

In Monroe County County, , plant Coreopsis after the last frost (around April 14) and before the first frost (around October 24). Best results when soil holds above 50°F.

What growing zone is Monroe County County, for Coreopsis?

Monroe County County sits in USDA Zone 7a. Coreopsis grows reliably in zones 3a through 9b, so it's a good fit here.

Can Coreopsis grow in Monroe County County's climate?

Yes — Coreopsis grows well in Monroe County County's temperate climate. Monroe County County averages a 193-day frost-free season, with last frost around April 14 and first frost around October 24.

🌱

Your Monroe County Garden Planner — Free

A 22-page printable planner built for Monroe County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Monroe County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.