When to Plant Cosmos in Knoxville, Tennessee (37915)

Location

Knoxville, Tennessee

ZIP Code

37915

USDA Zone

Last Frost

Sunday, April 5, 2026

📅 Planting Calendar

Direct Sow Outdoors Sunday, April 5, 2026

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 Knoxville?

Get your seeds now so they're ready by Sunday, April 5, 2026.

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Other Plants for Knoxville

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Growing Cosmos in Zone 7b

Cosmos (Cosmos bipinnatus) is a popular garden vegetable. In Knoxville, Tennessee, which is in USDA Hardiness Zone 7b, you should direct sow seeds around Sunday, April 5, 2026.

Your average last frost date is Sunday, April 5, 2026. Cosmos grows well when direct sown, as it doesn't transplant well or germinates quickly outdoors.