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When to Plant Zinnia in Riverside, California (92521)

Location

Riverside, California

ZIP Code

92521

USDA Zone

10a

Last Frost

Sunday, January 25, 2026

📅 Planting Calendar

Direct Sow Outdoors Sunday, February 1, 2026

Pro Tip: Sow Zinnia directly outdoors 1 week after your last frost date — it needs warm soil.

🌿 Plant Details

Scientific Name Zinnia elegans
Days to Maturity 60 days
Mature Height 12-36"
Spread 12"
Type Annual

☀️ Growing Requirements

☀️

Sun

Full Sun (6-8 hours)

💧

Water

Moderate (1 inch/week)

↔️

Spacing

12" apart

🌱

Planting Depth

0.25" deep

Seeds typically germinate in 5-10 days

Ready to Plant Zinnia in Riverside?

Get your seeds now so they're ready by Sunday, February 1, 2026.

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Growing Zinnia in Zone 10a

Zinnia (Zinnia elegans) is a popular garden vegetable. In Riverside, California, which is in USDA Hardiness Zone 10a, you should direct sow seeds around Sunday, February 1, 2026.

Your average last frost date is Sunday, January 25, 2026. Zinnia grows well when direct sown, as it doesn't transplant well or germinates quickly outdoors.