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When to plant Coreopsis in Kendall County County,

Kendall County County gardeners should plant Coreopsis between April 27 and May 18 in spring. With Kendall County County's Zone 5b climate (last frost April 20), Coreopsis needs 80 days to mature — plant by July 29 for a full harvest.

When to Plant Coreopsis in Kendall County, IL

Kendall County, Illinois Zone 5b June

This month in Kendall County, Illinois

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Kendall County, Illinois.

Avg. last frost April 20
Avg. first frost October 17
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 15 hrs
  1. Time to start coreopsis inside

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

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.

Kendall County, Illinois is in USDA Zone 5b. The average last spring frost is April 20 and the first fall frost is October 17, giving you a growing season of approximately 180 days.

At an elevation of 708 feet, Kendall County receives approximately 38.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Coreopsis during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Kendall County, IL (Zone 5b) Moderate season
180 days
Last Spring Frost April 20
180 growing days
First Fall Frost October 17

Kendall County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.8

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 10 Transplant: Apr 28 🌸 Bloom: Jul 7 – Oct 20
Recommended (50%) ✗ May not fit
Start indoors: Feb 16 Transplant: May 4 🌸 Bloom: Jul 13 – Oct 26
Safe Start (90%) ✗ May not fit
Start indoors: Mar 7 Transplant: May 23 🌸 Bloom: Aug 1 – 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 Kendall County

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

Soil pH

Your soil pH (6.1–6.8) is within Coreopsis's preferred range (5.5–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.9%) — 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 180-day season

Sow every 6.9 weeks. Last sowing by Jul 29 to harvest before frost.

Coreopsis Water Budget

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

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 1.7" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 2.2" 3.9" 0" ✅ Rainfall sufficient
May 2.2" 4.6" 0" ✅ Rainfall sufficient
Jun 2.2" 5.3" 0" ✅ Rainfall sufficient
Jul 2.2" 4.1" 0" ✅ Rainfall sufficient
Aug 2.2" 3.4" 0" ✅ Rainfall sufficient
Sep 2.2" 3" 0" ✅ Rainfall sufficient
Oct 2.2" 2.9" 0" ✅ Rainfall sufficient
Nov 2.9" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Kendall 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 ~962 GDD — county provides 2,475 GDD Excellent fit

Coreopsis Planting Timeline — Kendall County, IL

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors February 16 Feb 16 – Mar 2
Transplant Outdoors May 4 May 4 – May 18
Direct Sow April 27 Apr 27 – May 18
Bloom July 13 Jul 13 – Oct 26

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

Month-by-Month Timeline

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

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 5b

📆 Growing Season

180 days in Kendall County

Growing Tips for Coreopsis in Kendall County

Direct sow Coreopsis outdoors after April 20 in Kendall 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 Kendall County, IL?

Kendall County is in Zone 5b with an average last frost of April 20. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.

What planting zone is Kendall County, IL?

Kendall County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 20 and first fall frost is October 17.

When should I plant Coreopsis in Kendall County County, ?

In Kendall County County, , plant Coreopsis after the last frost (around April 20) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Kendall County County, for Coreopsis?

Kendall County County sits in USDA Zone 5b. Coreopsis grows reliably in zones 3a through 9b, so it's a good fit here.

Can Coreopsis grow in Kendall County County's climate?

Yes — Coreopsis grows well in Kendall County County's temperate climate. Kendall County County averages a 180-day frost-free season, with last frost around April 20 and first frost around October 17.

🌱

Your Kendall County Garden Planner — Free

A 22-page printable planner built for Kendall County (Zone 5b). 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 Kendall 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.