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When to plant Coreopsis in Greenlee County, AZ

Greenlee County's spring Coreopsis window runs April 15 through May 6. most warm-season crops establish quickly once soil holds above 60°F.

When to Plant Coreopsis in Greenlee County, AZ

Greenlee County, Arizona Zone 8a June

This month in Greenlee County, Arizona

Each item below is timed to Greenlee County, Arizona's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 22
Avg. first frost October 22
Soil temp (4") 69°F
Watering Critical
Pest pressure High
Daylight 14.2 hrs
  1. Sow coreopsis in trays indoors

    You're about 16 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Harvest coreopsis as they ripen

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

A few tasks this June that'll pay off in July
  • 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.

Greenlee County, Arizona is in USDA Zone 8a. The average last spring frost is April 22 and the first fall frost is October 22, giving you a growing season of approximately 183 days.

At an elevation of 4,156 feet, Greenlee County receives approximately 14.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°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. 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
Greenlee County, AZ (Zone 8a) Moderate season
183 days
Last Spring Frost April 22
183 growing days
First Fall Frost October 22

Greenlee County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.1-8.3

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 13 Transplant: Apr 10 🌸 Bloom: Jun 12 – Nov 6
Recommended (50%) ✗ May not fit
Start indoors: Feb 25 Transplant: Apr 22 🌸 Bloom: Jun 24 – Nov 18
Safe Start (90%) ✓ Fits season (308 days to spare)
Start indoors: Apr 23 Transplant: Jun 18 🌸 Bloom: Aug 20 – Jan 14

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 Greenlee County

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

Soil pH

Your soil pH (7.1–8.3) is more alkaline than Coreopsis prefers (5.5–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Greenlee 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 (0.9%). 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 183-day season

Sow every 6.9 weeks. Last sowing by Aug 03 to harvest before frost.

Coreopsis Water Budget

Plant needs
0.5″/week
Rainfall provides
0.3″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 624 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" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 0.8" 0" ❄️ Dormant
Apr 2.2" 0.5" 1.7" 🚿 Regular watering
May 2.2" 0.4" 1.8" 🚿 Regular watering
Jun 2.2" 0.5" 1.7" 🚿 Regular watering
Jul 2.2" 2.7" 0" ✅ Rainfall sufficient
Aug 2.2" 2.9" 0" ✅ Rainfall sufficient
Sep 2.2" 1.7" 0.5" 💧 Light watering
Oct 2.2" 1.3" 0.9" 💧 Light watering
Nov 0.9" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Greenlee 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 ~1,488 GDD — county provides 3,888 GDD Excellent fit

Coreopsis Planting Timeline — Greenlee County, AZ

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors February 25 Feb 25 – Mar 11
Transplant Outdoors April 22 Apr 22 – May 6
Direct Sow April 15 Apr 15 – May 6
Bloom June 24 Jun 24 – Nov 18

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 Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November Bloom
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · 1-2 times/week

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8a

📆 Growing Season

183 days in Greenlee County

Growing Tips for Coreopsis in Greenlee County

Direct sow Coreopsis outdoors after April 22 in Greenlee County when soil has warmed and frost danger has passed.

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

Common pests for Coreopsis in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

Greenlee County receives only 14" 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 Greenlee County, AZ?

Greenlee County is in Zone 8a 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 Greenlee County, AZ?

Greenlee County, Arizona is in USDA Hardiness Zone 8a. The average last spring frost is April 22 and first fall frost is October 22.

When should I plant Coreopsis in Greenlee County, AZ?

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

What growing zone is Greenlee County, AZ for Coreopsis?

Greenlee County sits in USDA Zone 8a. Coreopsis grows reliably in zones 3a through 9b, so it's a good fit here.

Can Coreopsis grow in Greenlee County's climate?

Yes — Coreopsis grows well in Greenlee County's temperate climate. Greenlee County averages a 183-day frost-free season, with last frost around April 22 and first frost around October 22.

🌱

Your Greenlee County Garden Planner — Free

A 22-page printable planner built for Greenlee County (Zone 8a). 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 Greenlee County, AZ. 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.