When should I plant Sunflower in Zone 10b?

Start Sunflower seeds indoors around Jan 7. Transplant outdoors after Feb 4. Expect first harvest around Apr 10.

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 Sunflower in Zone 10b?

Yes. Sunflower needs 90 days to harvest. Zone 10b has a 328-day growing season, which is sufficient. You can plant up to 17 successions.

🌻

🌻 Growing Sunflower in Zone 10b

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

Planting Calendar

Indoor

Outdoor

Harvest

Jan 7Dec 22

Season: Jan 28 – Dec 22 (328 days) · Succession: plant every 2 weeks (up to 17x)

Zone10b

Last FrostJan 28

First FrostDec 22

Season Length328 days

Days to Harvest90

SunFull Sun

Frost ToleranceNone

Spacing1/sqft (12" apart)

When to Plant Sunflower in Zone 10b

Start Seeds Indoors: Jan 7

Start Sunflower seeds indoors around Jan 7 (3 weeks before last frost). Optimal germination temperature: 75°F. Germinates in 7–14 days.

Transplant Outdoors: Feb 4

Transplant Sunflower seedlings outdoors after Feb 4. Wait until soil temperature reaches 55°F. Space plants at 1/sqft (12" apart). Harden off plants for a week before moving outside.

Harvest: Apr 10

First harvest approximately Apr 10 (~65 days from transplant). Continue harvesting until first frost (Dec 22).

Companion Planting

✅ Cucumbers✅ Squash ✅ Corn✅ Beans

❌ Potatoes

Sunflower in Other Zones

1a 1b 2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b 11a 11b 12a 12b 13a 13b

Plan Your Sunflower Garden

Track Sunflower from seed to harvest with personalized frost dates, watering recommendations, and companion planting visualization.

Start Free Sunflower Growing Guide