When to Plant Hollyhock in Mount Wilson, California (91023)

Location

Mount Wilson, California

ZIP Code

91023

USDA Zone

Last Frost

Friday, February 20, 2026

📅 Planting Calendar

Start Seeds Indoors Friday, January 9, 2026

Transplant Outdoors Friday, March 6, 2026

Pro Tip: Start Hollyhock seeds indoors 6 weeks before your last frost date, then transplant outdoors around Friday, March 6, 2026.

🌿 Plant Details

Scientific Name Alcea rosea

Days to Maturity 365 days

Mature Height 48-96"

Spread 24"

☀️ Growing Requirements

☀️

Sun

Full Sun (6-8 hours)

💧

Water

Moderate (1 inch/week)

↔️

Spacing

18" apart

🌱

Planting Depth

0.25" deep

Seeds typically germinate in 10-14 days

Ready to Plant Hollyhock in Mount Wilson?

Get your seeds now so they're ready by Friday, January 9, 2026.

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Growing Hollyhock in Zone 9a

Hollyhock (Alcea rosea) is a popular garden vegetable. In Mount Wilson, California, which is in USDA Hardiness Zone 9a, you should start seeds indoors around Friday, January 9, 2026.

Your average last frost date is Friday, February 20, 2026. Plan to transplant your Hollyhock seedlings outdoors around Friday, March 6, 2026, about 2 weeks after your last frost date.