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When to plant Coreopsis in Fairfield County, CT

Spring Coreopsis in Fairfield County goes in April 9–April 30, once nighttime temps stop dipping near freezing.

When to Plant Coreopsis in Fairfield County, CT

Fairfield County, Connecticut Zone 6b August

Your August gardening checklist

August is a pivotal month for Fairfield County, Connecticut gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 9
Avg. first frost November 3
Soil temp (4") 86°F
Watering Moderate
Pest pressure High
Daylight 13.7 hrs
  1. Pick coreopsis

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

Coming up in September — 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.

Fairfield County, Connecticut is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is November 3, giving you a growing season of approximately 208 days.

At an elevation of 617 feet, Fairfield County receives approximately 41 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Coreopsis during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Fairfield County, CT (Zone 6b) Long season
208 days
Last Spring Frost April 9
208 growing days
First Fall Frost November 3

Fairfield County Soil Profile

Soil Type

Silt Loam

Soil pH

5.1-6.4

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Start indoors: Jan 27 Transplant: Apr 7 🌸 Bloom: Jun 16 – Oct 13
Recommended (50%) ✓ Fits season (12 days to spare)
Start indoors: Feb 5 Transplant: Apr 16 🌸 Bloom: Jun 25 – Oct 22
Safe Start (90%) ✓ Fits season (18 days to spare)
Start indoors: Feb 25 Transplant: May 6 🌸 Bloom: Jul 15 – Nov 11

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 Fairfield County

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

Soil pH

Your soil pH (5.1–6.4) overlaps with Coreopsis's range (5.5–7.5), though not a perfect match.

Soil Texture

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

Drainage

Coreopsis prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Coreopsis.

How to Plant Coreopsis

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

Succession Planting Coreopsis

4
successive plantings in your 208-day season

Sow every 6.9 weeks. Last sowing by Aug 15 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

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 3.1" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 3.1" 0" ❄️ Dormant
Apr 2.2" 3.9" 0" ✅ Rainfall sufficient
May 2.2" 3.2" 0" ✅ Rainfall sufficient
Jun 2.2" 3.3" 0" ✅ Rainfall sufficient
Jul 2.2" 4.6" 0" ✅ Rainfall sufficient
Aug 2.2" 3.6" 0" ✅ Rainfall sufficient
Sep 2.2" 3.6" 0" ✅ Rainfall sufficient
Oct 2.2" 3.5" 0" ✅ Rainfall sufficient
Nov 2.2" 3.6" 0" ✅ Rainfall sufficient
Dec 2.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Fairfield 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 ~1,278 GDD — county provides 3,796 GDD Excellent fit

Coreopsis Planting Timeline — Fairfield County, CT

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors February 5 Feb 5 – Feb 19
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 9 Apr 9 – Apr 30
Bloom June 25 Jun 25 – Oct 22

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

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: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

208 days in Fairfield County

Growing Tips for Coreopsis in Fairfield County

Direct sow Coreopsis outdoors after April 09 in Fairfield 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 Fairfield County, CT?

Fairfield County is in Zone 6b with an average last frost of April 9. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.

What planting zone is Fairfield County, CT?

Fairfield County, Connecticut is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is November 3.

When should I plant Coreopsis in Fairfield County, CT?

In Fairfield County, CT, plant Coreopsis after the last frost (around April 9) and before the first frost (around November 3). Best results when soil holds above 50°F.

What growing zone is Fairfield County, CT for Coreopsis?

Fairfield County sits in USDA Zone 6b. Coreopsis grows reliably in zones 3a through 9b, so it's a good fit here.

Can Coreopsis grow in Fairfield County's climate?

Yes — Coreopsis grows well in Fairfield County's temperate climate. Fairfield County averages a 208-day frost-free season, with last frost around April 9 and first frost around November 3.

🌱

Your Fairfield County Garden Planner — Free

A 22-page printable planner built for Fairfield County (Zone 6b). 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 Fairfield County, CT. Local conditions may vary. Last updated: August 2026.

Sources & credits

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