Zinnia illustration

Growing Zinnia in Zone 10b

Zone 10b has a year-round growing season. Zinnia can be planted almost any time with proper planning. Last frost: Jan 28. First frost: Dec 22.

Planting Calendar

Indoor
Outdoor
Harvest
Dec 31Dec 22

Season: Jan 28 – Dec 22 (328 days)

Zone10b
Last FrostJan 28
First FrostDec 22
Season Length328 days
Days to Harvest60
SunFull Sun
Frost ToleranceNone
Spacing8/sqft

When to Plant Zinnia in Zone 10b

Start Seeds Indoors: Dec 31

Start Zinnia seeds indoors around Dec 31 (4 weeks before last frost). Optimal germination temperature: 75°F. Germinates in 5–10 days.

Transplant Outdoors: Feb 11

Transplant Zinnia seedlings outdoors after Feb 11. Wait until soil temperature reaches 60°F. Space plants at 8/sqft. Harden off plants for a week before moving outside.

Harvest: Apr 2

First harvest approximately Apr 2 (~50 days from transplant). Continue harvesting until first frost (Dec 22).

Frequently Asked Questions

When should I plant Zinnia in Zone 10b?

Start Zinnia seeds indoors around Dec 31. Transplant outdoors after Feb 11. Expect first harvest around Apr 2.

What is the last frost date for Zone 10b?

The average last spring frost date for Zone 10b is Jan 28. The first fall frost averages Dec 22, giving a 328-day growing season.

Can I grow Zinnia in Zone 10b?

Yes. Zinnia needs 60 days to harvest. Zone 10b has a 328-day growing season, which is sufficient.

What is the best month to plant Zinnia in Zone 10b?

The best time to start Zinnia in Zone 10b is Dec. Begin seeds indoors around Dec 31, then transplant outdoors after the last frost date of Jan 28.

How long does Zinnia take to harvest?

Zinnia takes approximately 60 days from planting to harvest. In Zone 10b, expect your first harvest around Apr 2.

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