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When to plant Cosmos in Mitchell County County,

Plant Cosmos in Mitchell County County, when soil hits 50°F — usually April 16. Continue planting through May 7 for the spring crop.

When to Plant Cosmos in Mitchell County, KS

Mitchell County, Kansas Zone 6a June

Your June game plan for Mitchell County, Kansas

Your Mitchell County, Kansas garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost April 16
Avg. first frost October 18
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Basket week: cosmos

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

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

Mitchell County, Kansas is in USDA Zone 6a. The average last spring frost is April 16 and the first fall frost is October 18, giving you a growing season of approximately 185 days.

At an elevation of 627 feet, Mitchell County receives approximately 34.3 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Cosmos to ensure they mature before fall.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Mitchell County, KS (Zone 6a) Moderate season
185 days
Last Spring Frost April 16
185 growing days
First Fall Frost October 18

Mitchell County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.1

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (15 days to spare)
Start indoors: Mar 15 Transplant: Apr 12 🌸 Bloom: Jun 21 – Sep 27
Recommended (50%) ✓ Fits season (17 days to spare)
Start indoors: Mar 19 Transplant: Apr 16 🌸 Bloom: Jun 25 – Oct 1
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: Apr 2 Transplant: Apr 30 🌸 Bloom: Jul 9 – Oct 15

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 Mitchell County

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

Soil pH

Your soil pH (6.7–7.1) is within Cosmos's preferred range (6.0–8.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Cosmos.

How to Plant Cosmos

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

Succession Planting Cosmos

3
successive plantings in your 185-day season

Sow every 6.9 weeks. Last sowing by Jul 20 to harvest before frost.

Cosmos Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/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 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 1" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 2.2" 3.6" 0" ✅ Rainfall sufficient
May 2.2" 4.6" 0" ✅ Rainfall sufficient
Jun 2.2" 5.9" 0" ✅ Rainfall sufficient
Jul 2.2" 4.5" 0" ✅ Rainfall sufficient
Aug 2.2" 3.6" 0" ✅ Rainfall sufficient
Sep 2.2" 3.6" 0" ✅ Rainfall sufficient
Oct 2.2" 2" 0.2" 💧 Light watering
Nov 1.3" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Mitchell 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 ~975 GDD — county provides 2,405 GDD Excellent fit

Cosmos Planting Timeline — Mitchell County, KS

Cosmos Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 16 Apr 16 – May 7
Bloom June 25 Jun 25 – Oct 1

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–8 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

185 days in Mitchell County

Growing Tips for Cosmos in Mitchell County

Direct sow Cosmos outdoors after April 16 in Mitchell 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.

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 Mitchell County, KS?

Mitchell County is in Zone 6a with an average last frost of April 16. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mitchell County, KS?

Mitchell County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 16 and first fall frost is October 18.

When should I plant Cosmos in Mitchell County County, ?

In Mitchell County County, , plant Cosmos after the last frost (around April 16) and before the first frost (around October 18). Best results when soil holds above 50°F.

What growing zone is Mitchell County County, for Cosmos?

Mitchell County County sits in USDA Zone 6a. Cosmos grows reliably in zones 2a through 11b, so it's a good fit here.

Can Cosmos grow in Mitchell County County's climate?

Yes — Cosmos grows well in Mitchell County County's temperate climate. Mitchell County County averages a 185-day frost-free season, with last frost around April 16 and first frost around October 18.

🌱

Your Mitchell County Garden Planner — Free

A 22-page printable planner built for Mitchell County (Zone 6a). 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 Mitchell County, KS. 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.