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When to Plant Cosmos in Hooker County, NE

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

Monthly Watering Guide for Cosmos

Cosmos needs approximately 1 inches of water per week (4.3" 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 4.3" 2.6" 1.7" 💧 Light watering
Jun 4.3" 1.7" 2.6" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 2" 2.3" 🚿 Regular watering
Sep 4.3" 1.5" 2.8" 🚿 Regular watering
Oct 4.3" 1.7" 2.6" 🚿 Regular 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 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

Low — drought tolerant

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–8 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

144 days in Hooker County

Growing Tips for Hooker County

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: August 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.