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When to Plant Cosmos in Wayne County, NE

Wayne County, Nebraska Zone 5b June

June in Wayne County, Nebraska — your action list

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

Avg. last frost May 1
Avg. first frost October 7
Soil temp (4") 64°F
Watering Moderate
Pest pressure High
Daylight 15.1 hrs
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.

Wayne County, Nebraska is in USDA Zone 5b. The average last spring frost is May 1 and the first fall frost is October 7, giving you a growing season of approximately 159 days.

At an elevation of 637 feet, Wayne County receives approximately 23.8 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
Wayne County, NE (Zone 5b) Moderate season
159 days
Last Spring Frost May 1
159 growing days
First Fall Frost October 7

Wayne County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.4

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (0 days to spare)
Start indoors: Mar 27 Transplant: Apr 24 🌸 Bloom: Jul 3 – Oct 2
Recommended (50%) ✗ May not fit
Start indoors: Apr 3 Transplant: May 1 🌸 Bloom: Jul 10 – Oct 9
Safe Start (90%) ✗ May not fit
Start indoors: Apr 16 Transplant: May 14 🌸 Bloom: Jul 23 – Oct 22

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 Wayne County

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

Soil pH

Your soil pH (6.6–7.4) is within Cosmos's preferred range (6.0–8.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.0%) — Cosmos will thrive.

How to Plant Cosmos

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

Succession Planting Cosmos

3
successive plantings in your 159-day season

Sow every 6.9 weeks. Last sowing by Jul 09 to harvest before frost.

Cosmos 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 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 1.4" 0" ❄️ Dormant
Apr 2.7" 0" ❄️ Dormant
May 2.2" 3.8" 0" ✅ Rainfall sufficient
Jun 2.2" 3.3" 0" ✅ Rainfall sufficient
Jul 2.2" 3" 0" ✅ Rainfall sufficient
Aug 2.2" 2.7" 0" ✅ Rainfall sufficient
Sep 2.2" 2.4" 0" ✅ Rainfall sufficient
Oct 2.2" 1.4" 0.8" 💧 Light watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Wayne 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 2,067 GDD Excellent fit

Cosmos Planting Timeline — Wayne County, NE

Cosmos Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 – Apr 17
Transplant Outdoors May 1 May 1 – May 15
Direct Sow May 1 May 1 – May 22
Bloom July 10 Jul 10 – Oct 9

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June
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 5b

📆 Growing Season

159 days in Wayne County

Growing Tips for Cosmos in Wayne County

Direct sow Cosmos outdoors after May 01 in Wayne 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.

Wayne County receives only 24" 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 Wayne County, NE?

Wayne County is in Zone 5b with an average last frost of May 1. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wayne County, NE?

Wayne County, Nebraska is in USDA Hardiness Zone 5b. The average last spring frost is May 1 and first fall frost is October 7.

🌱

Your Wayne County Garden Planner — Free

A 22-page printable planner built for Wayne 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 Wayne County, NE. 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.