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When to Plant Cosmos in Murray County, OK

Murray County, Oklahoma Zone 7b June

Your June gardening checklist

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Murray County, Oklahoma.

Avg. last frost March 28
Avg. first frost November 2
Soil temp (4") 77°F
Watering Moderate
Pest pressure High
Daylight 14.3 hrs
  1. Pick cosmos

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

Looking ahead to July
  • First harvests: cosmos

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Cosmos (Cosmos bipinnatus) is an airy, feathery-foliaged cottage garden annual from Mexico that thrives on neglect. It produces delicate daisy-like blooms in shades of pink, white, and magenta from midsummer until frost. Cosmos is a prolific self-sower — once established in a garden it often returns year after year without replanting. Excellent habitat plant for beneficial insects.

Murray County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 28 and the first fall frost is November 2, giving you a growing season of approximately 219 days.

At an elevation of 640 feet, Murray County receives approximately 23.2 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Cosmos during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Murray County, OK (Zone 7b) Long season
219 days
Last Spring Frost March 28
219 growing days
First Fall Frost November 2

Murray County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.7

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (32 days to spare)
Start indoors: Feb 21 Transplant: Mar 14 🌸 Bloom: May 23 – Sep 26
Recommended (50%) ✓ Fits season (30 days to spare)
Start indoors: Feb 28 Transplant: Mar 21 🌸 Bloom: May 30 – Oct 3
Safe Start (90%) ✓ Fits season (31 days to spare)
Start indoors: Mar 20 Transplant: Apr 10 🌸 Bloom: Jun 19 – Oct 23

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 Murray County

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

Soil pH

Your soil pH (6.5–7.7) is within Cosmos's preferred range (6.0–8.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Cosmos will thrive.

How to Plant Cosmos

0.3"
Planting Depth
12"
Between Plants
18"
Between Rows

Succession Planting Cosmos

4
successive plantings in your 219-day season

Sow every 6.9 weeks. Last sowing by Aug 04 to harvest before frost.

Cosmos Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 129 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Cosmos

Cosmos 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 Cosmos Needs Rainfall You Supplement Action
Jan 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 2.2" 1.4" 0.8" 💧 Light watering
Apr 2.2" 2.3" 0" ✅ Rainfall sufficient
May 2.2" 3.5" 0" ✅ Rainfall sufficient
Jun 2.2" 3.5" 0" ✅ Rainfall sufficient
Jul 2.2" 2.8" 0" ✅ Rainfall sufficient
Aug 2.2" 3.1" 0" ✅ Rainfall sufficient
Sep 2.2" 2.3" 0" ✅ Rainfall sufficient
Oct 2.2" 1.4" 0.8" 💧 Light watering
Nov 2.2" 0.8" 1.4" 🚿 Regular watering
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Murray County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Cosmos 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.

Cosmos needs ~1,538 GDD — county provides 4,489 GDD Excellent fit

Cosmos Planting Timeline — Murray County, OK

Cosmos Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 – Mar 14
Transplant Outdoors March 21 Mar 21 – Apr 4
Direct Sow March 21 Mar 21 – Apr 11
Bloom May 30 May 30 – Oct 3

Plant 0.3" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–8 · Your soil: ideal

🗺️ USDA Zone

Zone 7b

📆 Growing Season

219 days in Murray County

Growing Tips for Cosmos in Murray County

Direct sow Cosmos outdoors after March 28 in Murray County when soil has warmed and frost danger has passed.

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

Murray County receives only 23" of rain annually. Cosmos needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct-sow after last frost; cosmos germinates readily at 65-80°F in 7-10 days. Avoid rich soil — excess fertility produces lush foliage at the expense of blooms. Cosmos tolerates poor, dry soil exceptionally well. Pinch seedlings at 8 inches to encourage branching. Self-sows freely; allow some seed heads to mature and drop for a no-fuss perennial effect in warm climates.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cosmos in Murray County, OK?

Murray County is in Zone 7b with an average last frost of March 28. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Murray County, OK?

Murray County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 28 and first fall frost is November 2.

🌱

Your Murray County Garden Planner — Free

A 22-page printable planner built for Murray County (Zone 7b). 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 Murray County, OK. 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.