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When to plant Coreopsis in Gallatin County County,

For Coreopsis in Gallatin County County, the safe spring window opens around April 6 and closes around April 27. Last expected frost is April 6, first fall frost October 30, giving a 207-day growing season.

When to Plant Coreopsis in Gallatin County, IL

Gallatin County, Illinois Zone 7a June

This month in Gallatin County, Illinois

We've pulled the most time-sensitive tasks for Gallatin County, Illinois this June and put them front and centre. Tackle them in order.

Avg. last frost April 6
Avg. first frost October 30
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Get coreopsis seeds going inside

    Your window is short. These crops want several weeks of indoor growth before they go outside.

  2. Basket week: coreopsis

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

A few tasks this June that'll pay off in July
  • 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.

Gallatin County, Illinois is in USDA Zone 7a. The average last spring frost is April 6 and the first fall frost is October 30, giving you a growing season of approximately 207 days.

At an elevation of 1,391 feet, Gallatin County receives approximately 37 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
Gallatin County, IL (Zone 7a) Long season
207 days
Last Spring Frost April 6
207 growing days
First Fall Frost October 30
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Gallatin County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.8

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✓ Fits season (2 days to spare)
Start indoors: Jan 26 Transplant: Apr 6 🌸 Bloom: Jun 8 – Oct 19
Recommended (50%) ✓ Fits season (4 days to spare)
Start indoors: Feb 2 Transplant: Apr 13 🌸 Bloom: Jun 15 – Oct 26
Safe Start (90%) ✓ Fits season (12 days to spare)
Start indoors: Feb 13 Transplant: Apr 24 🌸 Bloom: Jun 26 – Nov 6

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 Gallatin County

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

Soil pH

Your soil pH (6.3–6.8) is within Coreopsis's preferred range (5.5–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.4%) — Coreopsis will thrive.

How to Plant Coreopsis

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

Succession Planting Coreopsis

4
successive plantings in your 207-day season

Sow every 6.9 weeks. Last sowing by Aug 11 to harvest before frost.

Coreopsis Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/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 1.7" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 2.2" 3.3" 0" ✅ Rainfall sufficient
May 2.2" 4.2" 0" ✅ Rainfall sufficient
Jun 2.2" 4.4" 0" ✅ Rainfall sufficient
Jul 2.2" 4.5" 0" ✅ Rainfall sufficient
Aug 2.2" 3.7" 0" ✅ Rainfall sufficient
Sep 2.2" 3.3" 0" ✅ Rainfall sufficient
Oct 2.2" 2.7" 0" ✅ Rainfall sufficient
Nov 2.6" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Gallatin 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 2,846 GDD Excellent fit

Coreopsis Planting Timeline — Gallatin County, IL

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors April 13 Apr 13 – Apr 27
Direct Sow April 6 Apr 6 – Apr 27
Bloom June 15 Jun 15 – Oct 26

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
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November
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

207 days in Gallatin County

Growing Tips for Coreopsis in Gallatin County

Direct sow Coreopsis outdoors after April 06 in Gallatin 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 Gallatin County, IL?

Gallatin County is in Zone 7a with an average last frost of April 6. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.

What planting zone is Gallatin County, IL?

Gallatin County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 6 and first fall frost is October 30.

When should I plant Coreopsis in Gallatin County, ?

In Gallatin County, , plant Coreopsis after the last frost (around April 6) and before the first frost (around October 30). Best results when soil holds above 50°F.

What growing zone is Gallatin County, for Coreopsis?

Gallatin 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 Gallatin County's climate?

Yes — Coreopsis grows well in Gallatin County's temperate climate. Gallatin County averages a 207-day frost-free season, with last frost around April 6 and first frost around October 30.

🌱

Your Gallatin County Garden Planner — Free

A 22-page printable planner built for Gallatin 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 Gallatin 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.