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When to Plant Coreopsis in Hartley County, TX

Hartley County, Texas Zone 7a June

June to-do list for Hartley County, Texas

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

Avg. last frost April 23
Avg. first frost October 17
Soil temp (4") 61°F
Watering High
Pest pressure High
Daylight 14.4 hrs
  1. Start coreopsis indoors

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

To set up a strong July, finish these tasks
  • 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.

Hartley County, Texas is in USDA Zone 7a. The average last spring frost is April 23 and the first fall frost is October 17, giving you a growing season of approximately 177 days.

At an elevation of 4,344 feet, Hartley County receives approximately 46.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Coreopsis may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Coreopsis will need more frequent watering and organic matter to retain nutrients.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Hartley County, TX (Zone 7a) Moderate season
177 days
Last Spring Frost April 23
177 growing days
First Fall Frost October 17

Hartley County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.1

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 12 Transplant: Apr 23 🌸 Bloom: Jun 25 – Nov 5
Recommended (50%) ✗ May not fit
Start indoors: Feb 19 Transplant: Apr 30 🌸 Bloom: Jul 2 – Nov 12
Safe Start (90%) ✗ May not fit
Start indoors: Mar 3 Transplant: May 12 🌸 Bloom: Jul 14 – Nov 24

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 Hartley County

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

Soil pH

Your soil pH (7.2–8.1) is more alkaline than Coreopsis prefers (5.5–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Hartley County warms quickly in spring but drains fast. Coreopsis will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Coreopsis.

Organic Matter

Organic matter is low (1.1%). Add 2-3 inches of compost before planting Coreopsis.

How to Plant Coreopsis

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

Succession Planting Coreopsis

3
successive plantings in your 177-day season

Sow every 6.9 weeks. Last sowing by Jul 29 to harvest before frost.

Coreopsis Water Budget

Plant needs
0.5″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 2.7" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 2.2" 1.3" 0.9" 💧 Light watering
May 2.2" 1.1" 1.1" 🚿 Regular watering
Jun 2.2" 1.4" 0.8" 💧 Light watering
Jul 2.2" 8.5" 0" ✅ Rainfall sufficient
Aug 2.2" 9.9" 0" ✅ Rainfall sufficient
Sep 2.2" 6" 0" ✅ Rainfall sufficient
Oct 2.2" 4.5" 0" ✅ Rainfall sufficient
Nov 2.3" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Hartley 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 ~1,540 GDD — county provides 3,894 GDD Excellent fit

Coreopsis Planting Timeline — Hartley County, TX

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors April 30 Apr 30 – May 14
Direct Sow April 23 Apr 23 – May 14
Bloom July 2 Jul 2 – Nov 12

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 7a

📆 Growing Season

177 days in Hartley County

Growing Tips for Coreopsis in Hartley County

Direct sow Coreopsis outdoors after April 23 in Hartley County when soil has warmed and frost danger has passed.

Sandy soil in Hartley County dries quickly — mulch Coreopsis with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Hartley County, provide afternoon shade for Coreopsis and water deeply in the morning.

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 Hartley County, TX?

Hartley County is in Zone 7a with an average last frost of April 23. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hartley County, TX?

Hartley County, Texas is in USDA Hardiness Zone 7a. The average last spring frost is April 23 and first fall frost is October 17.

🌱

Your Hartley County Garden Planner — Free

A 22-page printable planner built for Hartley County (Zone 7a). 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 Hartley County, TX. 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.