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When to Plant Cosmos in Hooker County, NE

Hooker County, Nebraska Zone 5b June

Hooker County, Nebraska gardeners: here's your June plan

Here's what deserves your attention in Hooker County, Nebraska this month. Everything below is tailored to Zone 5b and timed around your local frost dates.

Avg. last frost May 13
Avg. first frost October 4
Soil temp (4") 67°F
Watering High
Pest pressure High
Daylight 15 hrs
  1. Sow cosmos in trays indoors

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

Get ahead of 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.

Hooker County, Nebraska is in USDA Zone 5b. The average last spring frost is May 13 and the first fall frost is October 4, giving you a growing season of approximately 144 days.

At an elevation of 737 feet, Hooker County receives approximately 21.1 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Cosmos to ensure they mature before fall.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Hooker County, NE (Zone 5b) Short season
144 days
Last Spring Frost May 13
144 growing days
First Fall Frost October 4

Hooker County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.1

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 10 Transplant: May 8 🌸 Bloom: Jul 17 – Oct 16
Recommended (50%) ✗ May not fit
Start indoors: Apr 15 Transplant: May 13 🌸 Bloom: Jul 22 – Oct 21
Safe Start (90%) ✗ May not fit
Start indoors: Apr 24 Transplant: May 22 🌸 Bloom: Jul 31 – Oct 30

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 Hooker County

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

Soil pH

Your soil pH (6.2–7.1) is within Cosmos's preferred range (6.0–8.0).

Soil Texture

The loam soil in Hooker 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

2
successive plantings in your 144-day season

Sow every 6.9 weeks. Last sowing by Jul 06 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 8/10 — 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 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 2.2" 2.6" 0" ✅ Rainfall sufficient
Jun 2.2" 1.7" 0.5" 💧 Light watering
Jul 2.2" 1.8" 0.4" 💧 Light watering
Aug 2.2" 2" 0.2" 💧 Light watering
Sep 2.2" 1.5" 0.7" 💧 Light watering
Oct 2.2" 1.7" 0.5" 💧 Light watering
Nov 1.7" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Hooker 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 ~806 GDD — county provides 1,548 GDD Excellent fit

Cosmos Planting Timeline — Hooker County, NE

Cosmos Planting Calendar

Activity When Date Range
Start Indoors April 15 Apr 15 – Apr 29
Transplant Outdoors May 13 May 13 – May 27
Direct Sow May 13 May 13 – Jun 3
Bloom July 22 Jul 22 – Oct 21

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 Direct Sow
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

144 days in Hooker County

Growing Tips for Cosmos in Hooker County

Direct sow Cosmos outdoors after May 13 in Hooker 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.

Hooker County receives only 21" 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 Hooker County, NE?

Hooker County is in Zone 5b with an average last frost of May 13. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hooker County, NE?

Hooker County, Nebraska is in USDA Hardiness Zone 5b. The average last spring frost is May 13 and first fall frost is October 4.

🌱

Your Hooker County Garden Planner — Free

A 22-page printable planner built for Hooker 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 Hooker 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.