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When to plant Coreopsis in Atchison County, MO

Atchison County sits in USDA Zone 5b. Plant Coreopsis between April 29 (after last frost on April 22) and May 20.

When to Plant Coreopsis in Atchison County, MO

Atchison County, Missouri Zone 5b July

This month in Atchison County, Missouri

July rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Atchison County, Missouri.

Avg. last frost April 22
Avg. first frost October 13
Soil temp (4") 76°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Harvest coreopsis as they ripen

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

August prep starts now
  • 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.

Atchison County, Missouri is in USDA Zone 5b. The average last spring frost is April 22 and the first fall frost is October 13, giving you a growing season of approximately 174 days.

At an elevation of 1,206 feet, Atchison County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Coreopsis to ensure they mature before fall.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Atchison County, MO (Zone 5b) Moderate season
174 days
Last Spring Frost April 22
174 growing days
First Fall Frost October 13

Atchison County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 11 Transplant: Apr 29 🌸 Bloom: Jul 8 – Oct 21
Recommended (50%) ✗ May not fit
Start indoors: Feb 18 Transplant: May 6 🌸 Bloom: Jul 15 – Oct 28
Safe Start (90%) ✗ May not fit
Start indoors: Mar 3 Transplant: May 19 🌸 Bloom: Jul 28 – Nov 10

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 Atchison County

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

Soil pH

Your soil pH (5.3–6.8) overlaps with Coreopsis's range (5.5–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Coreopsis.

How to Plant Coreopsis

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

Succession Planting Coreopsis

3
successive plantings in your 174-day season

Sow every 6.9 weeks. Last sowing by Jul 25 to harvest before frost.

Coreopsis Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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 1.5" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 3.1" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 4.4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 4.2" 0" ✅ Rainfall sufficient
Aug 2.2" 4.3" 0" ✅ Rainfall sufficient
Sep 2.2" 4.1" 0" ✅ Rainfall sufficient
Oct 2.2" 3" 0" ✅ Rainfall sufficient
Nov 3.2" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Atchison 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 ~858 GDD — county provides 2,131 GDD Excellent fit

Coreopsis Planting Timeline — Atchison County, MO

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 – Mar 4
Transplant Outdoors May 6 May 6 – May 20
Direct Sow April 29 Apr 29 – May 20
Bloom July 15 Jul 15 – Oct 28

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: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

174 days in Atchison County

Growing Tips for Coreopsis in Atchison County

Direct sow Coreopsis outdoors after April 22 in Atchison 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 Atchison County, MO?

Atchison County is in Zone 5b with an average last frost of April 22. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.

What planting zone is Atchison County, MO?

Atchison County, Missouri is in USDA Hardiness Zone 5b. The average last spring frost is April 22 and first fall frost is October 13.

When should I plant Coreopsis in Atchison County, MO?

In Atchison County, MO, plant Coreopsis after the last frost (around April 22) and before the first frost (around October 13). Best results when soil holds above 50°F.

What growing zone is Atchison County, MO for Coreopsis?

Atchison 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 Atchison County's climate?

Yes — Coreopsis grows well in Atchison County's temperate climate. Atchison County averages a 174-day frost-free season, with last frost around April 22 and first frost around October 13.

🌱

Your Atchison County Garden Planner — Free

A 22-page printable planner built for Atchison 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 Atchison County, MO. Local conditions may vary. Last updated: July 2026.

Sources & credits

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