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When to Plant Coreopsis in Thurston County, NE

Thurston County, Nebraska Zone 5a June

June in the garden — Thurston County, Nebraska

Welcome to June in Zone 5a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 28
Avg. first frost October 10
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 15.1 hrs
  1. Fire up the seed-starting tray: coreopsis

    These need a head start before your last frost (April 28). Sow into cells now so you're ready to transplant in a few weeks.

Before July arrives, get these ready
  • 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.

Thurston County, Nebraska is in USDA Zone 5a. The average last spring frost is April 28 and the first fall frost is October 10, giving you a growing season of approximately 165 days.

At an elevation of 584 feet, Thurston County receives approximately 31.5 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Coreopsis during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Thurston County, NE (Zone 5a) Moderate season
165 days
Last Spring Frost April 28
165 growing days
First Fall Frost October 10
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Thurston County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.3

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 17 Transplant: May 5 🌸 Bloom: Jul 14 – Oct 20
Recommended (50%) ✗ May not fit
Start indoors: Feb 24 Transplant: May 12 🌸 Bloom: Jul 21 – Oct 27
Safe Start (90%) ✗ May not fit
Start indoors: Mar 12 Transplant: May 28 🌸 Bloom: Aug 6 – Nov 12

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 Thurston County

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

Soil pH

Your soil pH (6.6–7.3) is within Coreopsis's preferred range (5.5–7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (3.2%). 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 165-day season

Sow every 6.9 weeks. Last sowing by Jul 22 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 0.9" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 4.3" 0" ✅ Rainfall sufficient
Jun 2.2" 4.8" 0" ✅ Rainfall sufficient
Jul 2.2" 4.7" 0" ✅ Rainfall sufficient
Aug 2.2" 3.5" 0" ✅ Rainfall sufficient
Sep 2.2" 2.9" 0" ✅ Rainfall sufficient
Oct 2.2" 2.3" 0" ✅ Rainfall sufficient
Nov 0.9" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Thurston 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 ~1,068 GDD — county provides 2,516 GDD Excellent fit

Coreopsis Planting Timeline — Thurston County, NE

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors February 24 Feb 24 – Mar 10
Transplant Outdoors May 12 May 12 – May 26
Direct Sow May 5 May 5 – May 26
Bloom July 21 Jul 21 – Oct 27

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April
May Transplant Outdoors Direct Sow
June
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 5a

📆 Growing Season

165 days in Thurston County

Growing Tips for Coreopsis in Thurston County

Direct sow Coreopsis outdoors after April 28 in Thurston 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 Thurston County, NE?

Thurston County is in Zone 5a with an average last frost of April 28. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.

What planting zone is Thurston County, NE?

Thurston County, Nebraska is in USDA Hardiness Zone 5a. The average last spring frost is April 28 and first fall frost is October 10.

🌱

Your Thurston County Garden Planner — Free

A 22-page printable planner built for Thurston County (Zone 5a). 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 Thurston County, NE. 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.