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When to Plant Cosmos in Burton, Ohio (44021)

Location

Burton, Ohio

ZIP Code

44021

USDA Zone

6a

Last Frost

Monday, April 20, 2026

📅 Your 2026 Planting Dates

Direct Sow Outdoors

Monday, April 20, 2026

Based on last frost Monday, April 20, 2026 · Zone 6a

Pro tip: Sow Cosmos directly outdoors around your last frost date when soil starts to warm.

🌿 Plant Details

Scientific Name Cosmos bipinnatus
Days to Maturity 60 days
Mature Height 24-60"
Spread 18"
Type Annual

☀️ Growing Requirements

☀️

Sun

Full Sun (6-8 hours)

💧

Water

Low-Moderate

↔️

Spacing

18" apart

🌱

Planting Depth

0.25" deep

Seeds typically germinate in 7-14 days

Ready to Plant Cosmos in Burton?

Get your seeds now so they're ready by Monday, April 20, 2026.

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🤝 Good Companions

CornSquashTomato
🤝

Full Companion Planting Guide for Cosmos

See which plants help Cosmos thrive, which to keep away, and raised bed layout tips →

🛠️ Supplies You'll Need

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🌾 Seed Saving Guide

🟢 Easy
✅ Open-pollinated — seeds grow true to parent

When to Harvest Seed

Harvest narrow seed heads when flower petals drop and the base turns brown and dry.

Processing

Pull seeds directly from dried flower heads, dry 1 week in an open envelope.

Seed Viability

Up to 3 years when stored cool, dark, and dry.

Pro Tip

Cosmos cross freely within the species — isolate by 150 feet from other cosmos for pure color.

🪴

Raised Bed Planting Guides

A 4×8 bed fits 14 plants of Cosmos. See plant counts, spacing grids, and companion pairings for every bed size →

Frequently Asked Questions

When should I plant Cosmos in Burton, Ohio? +

In Burton (Zone 6a), direct sow Cosmos outdoors around Monday, April 20, 2026.

What is the last frost date for Burton, Ohio? +

The average last spring frost date for Burton, Ohio (ZIP 44021) is around Monday, April 20, 2026. This is based on NOAA climate normals for USDA Zone 6a.

How long does Cosmos take to grow? +

Cosmos typically matures in about 60 days from direct sowing. In Burton, that means you can expect harvest around Monday, April 20, 2026 plus 60 days.

Should I start Cosmos indoors or direct sow in Ohio? +

Cosmos does best when direct sown outdoors. In Burton, sow directly around Monday, April 20, 2026.

Other Plants for Burton

Growing Cosmos in Zone 6a

Cosmos (Cosmos bipinnatus) is a popular garden vegetable. In Burton, Ohio, which is in USDA Hardiness Zone 6a, you should direct sow seeds around Monday, April 20, 2026.

Your average last frost date is Monday, April 20, 2026. Cosmos grows well when direct sown, as it doesn't transplant well or germinates quickly outdoors.