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When to plant Coreopsis in Miller County, MO

Miller County's spring Coreopsis window runs April 6 through April 27. time plantings around the expected last-frost window for best survival.

When to Plant Coreopsis in Miller County, MO

Miller County, Missouri Zone 6b June

This month in Miller County, Missouri

Welcome to June in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 6
Avg. first frost October 27
Soil temp (4") 72°F
Watering Moderate
Pest pressure High
Daylight 14.6 hrs
  1. Get coreopsis seeds going inside

    Label every cell. You will absolutely forget which is which otherwise.

  2. Basket week: coreopsis

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Get ahead of 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.

Miller County, Missouri is in USDA Zone 6b. The average last spring frost is April 6 and the first fall frost is October 27, giving you a growing season of approximately 204 days.

At an elevation of 1,086 feet, Miller County receives approximately 30.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Coreopsis during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Miller County, MO (Zone 6b) Long season
204 days
Last Spring Frost April 6
204 growing days
First Fall Frost October 27

Miller County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.7

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✓ Fits season (7 days to spare)
Start indoors: Jan 27 Transplant: Apr 7 🌸 Bloom: Jun 16 – Oct 13
Recommended (50%) ✓ Fits season (8 days to spare)
Start indoors: Feb 2 Transplant: Apr 13 🌸 Bloom: Jun 22 – Oct 19
Safe Start (90%) ✓ Fits season (8 days to spare)
Start indoors: Feb 17 Transplant: Apr 28 🌸 Bloom: Jul 7 – Nov 3

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 Miller County

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

Soil pH

Your soil pH (5.7–6.7) is within Coreopsis's preferred range (5.5–7.5).

Soil Texture

The silt loam soil in Miller 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 (2.4%). 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 204-day season

Sow every 6.9 weeks. Last sowing by Aug 08 to harvest before frost.

Coreopsis Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/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 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.2" 3.4" 0" ✅ Rainfall sufficient
May 2.2" 4.2" 0" ✅ Rainfall sufficient
Jun 2.2" 3.6" 0" ✅ Rainfall sufficient
Jul 2.2" 3.1" 0" ✅ Rainfall sufficient
Aug 2.2" 3.1" 0" ✅ Rainfall sufficient
Sep 2.2" 3.1" 0" ✅ Rainfall sufficient
Oct 2.2" 2.4" 0" ✅ Rainfall sufficient
Nov 1.8" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Miller 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 ~1,172 GDD — county provides 3,417 GDD Excellent fit

Coreopsis Planting Timeline — Miller County, MO

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 22 Jun 22 – Oct 19

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: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

204 days in Miller County

Growing Tips for Coreopsis in Miller County

Direct sow Coreopsis outdoors after April 06 in Miller 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 Miller County, MO?

Miller County is in Zone 6b 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 Miller County, MO?

Miller County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 6 and first fall frost is October 27.

When should I plant Coreopsis in Miller County, MO?

In Miller County, MO, plant Coreopsis after the last frost (around April 6) and before the first frost (around October 27). Best results when soil holds above 50°F.

What growing zone is Miller County, MO for Coreopsis?

Miller 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 Miller County's climate?

Yes — Coreopsis grows well in Miller County's temperate climate. Miller County averages a 204-day frost-free season, with last frost around April 6 and first frost around October 27.

🌱

Your Miller County Garden Planner — Free

A 22-page printable planner built for Miller 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 Miller County, MO. 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.