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When to plant Coreopsis in Teller County County,

In Teller County County, Coreopsis is a single-season spring crop — there's no second fall window. Plant May 18–June 8 for an 80-day harvest, finishing well before the October 6 first frost.

When to Plant Coreopsis in Teller County, CO

Teller County, Colorado Zone 5b June

This month in Teller County, Colorado

Your garden in Teller County, Colorado is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost May 11
Avg. first frost October 6
Soil temp (4") 50°F
Watering High
Pest pressure High
Daylight 14.7 hrs
Get ahead of July
  • Starting indoors: 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.

Teller County, Colorado is in USDA Zone 5b. The average last spring frost is May 11 and the first fall frost is October 6, giving you a growing season of approximately 148 days.

At an elevation of 6,538 feet, Teller County receives approximately 19.5 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Coreopsis to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Coreopsis successfully. Mulch heavily to conserve soil moisture.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Teller County, CO (Zone 5b) Short season
148 days
Last Spring Frost May 11
148 growing days
First Fall Frost October 6
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Teller County Soil Profile

Soil Type

Loam

Soil pH

6.4-8.1

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 2 Transplant: May 18 🌸 Bloom: Jul 27 – Nov 9
Recommended (50%) ✗ May not fit
Start indoors: Mar 9 Transplant: May 25 🌸 Bloom: Aug 3 – Nov 16
Safe Start (90%) ✗ May not fit
Start indoors: Mar 25 Transplant: Jun 10 🌸 Bloom: Aug 19 – Dec 2

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 Teller County

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

Soil pH

Your soil pH (6.4–8.1) overlaps with Coreopsis's range (5.5–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). 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 148-day season

Sow every 6.9 weeks. Last sowing by Jul 18 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
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 1.3" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 2.2" 2.4" 0" ✅ Rainfall sufficient
Jun 2.2" 1.3" 0.9" 💧 Light watering
Jul 2.2" 1.5" 0.7" 💧 Light watering
Aug 2.2" 1.7" 0.5" 💧 Light watering
Sep 2.2" 1.7" 0.5" 💧 Light watering
Oct 2.2" 1.9" 0.3" 💧 Light watering
Nov 1.3" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Teller 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 ~910 GDD — county provides 1,924 GDD Excellent fit

Coreopsis Planting Timeline — Teller County, CO

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 – Mar 23
Transplant Outdoors May 25 May 25 – Jun 8
Direct Sow May 18 May 18 – Jun 8
Bloom August 3 Aug 3 – Nov 16

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
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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: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

148 days in Teller County

Growing Tips for Coreopsis in Teller County

Direct sow Coreopsis outdoors after May 11 in Teller 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.

Teller County receives only 20" 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 Teller County, CO?

Teller County is in Zone 5b with an average last frost of May 11. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.

What planting zone is Teller County, CO?

Teller County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 11 and first fall frost is October 6.

When should I plant Coreopsis in Teller County County, ?

In Teller County County, , plant Coreopsis after the last frost (around May 11) and before the first frost (around October 6). Best results when soil holds above 50°F.

What growing zone is Teller County County, for Coreopsis?

Teller County 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 Teller County County's climate?

Yes — Coreopsis grows well in Teller County County's temperate climate. Teller County County averages a 148-day frost-free season, with last frost around May 11 and first frost around October 6.

🌱

Your Teller County Garden Planner — Free

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