Zinnia illustration

Growing Zinnia in Zone 11b

Zone 11b has a year-round growing season. Zinnia can be planted almost any time with proper planning. Last frost: Jan 15. First frost: Dec 31.

Planting Calendar

Indoor
Outdoor
Harvest
Dec 18Dec 31

Season: Jan 15 – Dec 31 (350 days)

Zone11b
Last FrostJan 15
First FrostDec 31
Season Length350 days
Days to Harvest60
SunFull Sun
Frost ToleranceNone
Spacing8/sqft

When to Plant Zinnia in Zone 11b

Start Seeds Indoors: Dec 18

Start Zinnia seeds indoors around Dec 18 (4 weeks before last frost). Optimal germination temperature: 75°F. Germinates in 5–10 days.

Transplant Outdoors: Jan 29

Transplant Zinnia seedlings outdoors after Jan 29. Wait until soil temperature reaches 60°F. Space plants at 8/sqft. Harden off plants for a week before moving outside.

Harvest: Mar 20

First harvest approximately Mar 20 (~50 days from transplant). Continue harvesting until first frost (Dec 31).

Frequently Asked Questions

When should I plant Zinnia in Zone 11b?

Start Zinnia seeds indoors around Dec 18. Transplant outdoors after Jan 29. Expect first harvest around Mar 20.

What is the last frost date for Zone 11b?

The average last spring frost date for Zone 11b is Jan 15. The first fall frost averages Dec 31, giving a 350-day growing season.

Can I grow Zinnia in Zone 11b?

Yes. Zinnia needs 60 days to harvest. Zone 11b has a 350-day growing season, which is sufficient.

What is the best month to plant Zinnia in Zone 11b?

The best time to start Zinnia in Zone 11b is Dec. Begin seeds indoors around Dec 18, then transplant outdoors after the last frost date of Jan 15.

How long does Zinnia take to harvest?

Zinnia takes approximately 60 days from planting to harvest. In Zone 11b, expect your first harvest around Mar 20.

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