Tithonia (Mexican Sunflower) in Zone 2a & 2b
Tithonia rotundifolia
When to plant tithonia (mexican sunflower) in zone 2b
Zones 2a and 2b share the same average frost dates in our data, so this page covers both.
Method: Either: Start indoors for an earlier harvest, or direct-sow outside for less fuss. Tithonia (Mexican Sunflower) tolerates either.
| Start indoors | Apr 8–Apr 15 |
|---|---|
| Direct sow / transplant outside | Jun 3–Jun 10 |
| Estimated bloom | Aug 30–Sep 6 (~88 days after planting) |
Spacing: about 2 square feet per plant (square-foot-gardening spacing). Mature height: 4-6 ft.

Tithonia, better known as Mexican sunflower, is a fast-growing, heat-loving annual that produces vivid orange-red blooms on tall, sturdy stems late in the season, just as many other cut flowers are winding down.
How tithonia (mexican sunflower) fits zone 2's season
Zone 2b's frost-free window runs about 104 days, from May 20 to September 1. Tithonia (Mexican Sunflower) needs about 88 days from sowing to first harvest.
Good companions
No standout companions recorded yet for Tithonia (Mexican Sunflower).
Where to buy tithonia seeds
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See it growing
Search YouTube for "growing tithonia (mexican sunflower)" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 2b calendar · Full companion planting guide · Full plant profile · Plan your beds in the Garden Designer →

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Growing Tithonia (Mexican Sunflower) in USDA zone 2b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
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