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When to plant Coreopsis in Elbert County, CO

Elbert County's short 144-day growing season means one Coreopsis planting between May 19 and June 9. No fall crop in Zone 5b.

When to Plant Coreopsis in Elbert County, CO

Elbert County, Colorado Zone 5b July

July to-do list for Elbert County, Colorado

If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 12
Avg. first frost October 3
Soil temp (4") 60°F
Watering High
Pest pressure High
Daylight 14.5 hrs
  1. Start coreopsis under lights

    You're about 12 weeks out from your last frost — the perfect window to get these germinating indoors.

Looking ahead to August
  • 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.

Elbert County, Colorado is in USDA Zone 5b. The average last spring frost is May 12 and the first fall frost is October 3, giving you a growing season of approximately 144 days.

At an elevation of 5,587 feet, Elbert County receives approximately 22.1 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
Elbert County, CO (Zone 5b) Short season
144 days
Last Spring Frost May 12
144 growing days
First Fall Frost October 3

Elbert County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.7

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 1 Transplant: May 17 🌸 Bloom: Jul 26 – Nov 8
Recommended (50%) ✗ May not fit
Start indoors: Mar 10 Transplant: May 26 🌸 Bloom: Aug 4 – Nov 17
Safe Start (90%) ✗ May not fit
Start indoors: Mar 26 Transplant: Jun 11 🌸 Bloom: Aug 20 – Dec 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 Elbert County

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

Soil pH

Your soil pH (6.2–7.7) overlaps with Coreopsis's range (5.5–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Coreopsis.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Coreopsis.

How to Plant Coreopsis

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

Succession Planting Coreopsis

2
successive plantings in your 144-day season

Sow every 6.9 weeks. Last sowing by Jul 15 to harvest before frost.

Coreopsis Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 8 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 2.2" 2.4" 0" ✅ Rainfall sufficient
Jun 2.2" 1.7" 0.5" 💧 Light watering
Jul 2.2" 1.9" 0.3" 💧 Light watering
Aug 2.2" 2.3" 0" ✅ Rainfall sufficient
Sep 2.2" 2" 0.2" 💧 Light watering
Oct 2.2" 1.9" 0.3" 💧 Light watering
Nov 1.8" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Elbert 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 2,196 GDD Excellent fit

Coreopsis Planting Timeline — Elbert County, CO

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors May 26 May 26 – Jun 9
Direct Sow May 19 May 19 – Jun 9
Bloom August 4 Aug 4 – Nov 17

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July
August Bloom
September Bloom
October Bloom
November Bloom
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

144 days in Elbert County

Growing Tips for Coreopsis in Elbert County

Direct sow Coreopsis outdoors after May 12 in Elbert 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.

Elbert County receives only 22" of rain annually. Coreopsis needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Elbert County, CO?

Elbert County is in Zone 5b with an average last frost of May 12. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.

What planting zone is Elbert County, CO?

Elbert County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 12 and first fall frost is October 3.

When should I plant Coreopsis in Elbert County, CO?

In Elbert County, CO, plant Coreopsis after the last frost (around May 12) and before the first frost (around October 3). Best results when soil holds above 50°F.

What growing zone is Elbert County, CO for Coreopsis?

Elbert 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 Elbert County's climate?

Yes — Coreopsis grows well in Elbert County's temperate climate. Elbert County averages a 144-day frost-free season, with last frost around May 12 and first frost around October 3.

🌱

Your Elbert County Garden Planner — Free

A 22-page printable planner built for Elbert 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 Elbert County, CO. 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.