Growing Tithonia: A Complete Profile
By Growing Home Greens Team · July 25, 2026
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.
Sowing it
Seed needs light to germinate, so barely cover it. Direct-sow once soil has warmed to 70-85°F, or get a jump start by sowing indoors about 6 weeks before your last frost date and transplanting out after frost danger passes. Expect first blooms around 85-90 days from seeding. ‘Torch’ is the classic tall type; if you want the height, plant that one and skip the compact cultivars bred for smaller beds.
Giving it room
Tithonia is low-fuss once established, but it grows tall, 4-6 feet, and can shade or crowd smaller neighbors if not given enough room or placed at the back of a bed.
A late-season butterfly magnet for the north edge
Place tithonia on the north edge of a bed so it doesn’t shade shorter plants, and expect it to become a butterfly magnet through late summer and fall, right when many earlier-blooming flowers have already peaked.
Sources: Mexican Sunflower (Tithonia), Johnny’s Selected Seeds; How to Grow Mexican Sunflowers (Tithonia rotundifolia) for Pollinators & Summer Color, Clemson Home & Garden Information Center.
Companion planting guide for Tithonia (Mexican Sunflower) · Find your planting dates
Typically viable in USDA zones 2-11. Not sure your zone? Look it up by ZIP code.
Mature height: 4-6 ft
Method: Either: Start indoors for an earlier harvest, or direct-sow outside for less fuss. Either works.
When to plant tithonia (Mexican sunflower), by zone
Every zone tithonia (Mexican sunflower) grows in. Pick your zone in the header and it will be highlighted here. Each zone links to its full page.
| Zone | Start indoors | Sow or plant out | Bloom |
|---|---|---|---|
| 2a & 2b | Apr 8–Apr 15 | Jun 3–Jun 10 | Aug 30–Sep 6 |
| 3a & 3b | Apr 18–Apr 25 | Jun 13–Jun 20 | Sep 9–Sep 16 |
| 4a & 4b | Apr 3–Apr 10 | May 29–Jun 5 | Aug 25–Sep 1 |
| 5a & 5b | Mar 29–Apr 5 | May 24–May 31 | Aug 20–Aug 27 |
| 6a & 6b | Mar 14–Mar 21 | May 9–May 16 | Aug 5–Aug 12 |
| 7a & 7b | Feb 27–Mar 6 | Apr 24–May 1 | Jul 21–Jul 28 |
| 8a & 8b | Feb 11–Feb 18 | Apr 8–Apr 15 | Jul 5–Jul 12 |
| 9a & 9b | Jan 4–Jan 11 | Mar 1–Mar 8 | May 28–Jun 4 |
| 10a & 10b | Dec 19–Dec 26 | Feb 13–Feb 20 | May 12–May 19 |
| 11a & 11b | Nov 20–Nov 27 | Jan 15–Jan 22 | Apr 13–Apr 20 |
Bloom dates are about 88 days after the sow or plant-out date, not after starting seeds indoors.
Zone 2 sows before zone 3 here, which looks wrong and is not. USDA zones rank winter cold, not season length, and zone 2 is mostly interior Alaska, where hard winters come with warm summers. More on what a zone measures.
See exact start-indoors, direct-sow, and harvest dates for your zone →
How many Tithonia (Mexican Sunflower) plants fit per square foot?
Spacing: about 2 square feet per plant (square-foot-gardening spacing). Mature height: 4-6 ft.
Varieties worth considering
- Torch (Tithonia rotundifolia 'Torch'): The original All-America Selections winner from 1951 and still the standard, bright orange-red type that reaches the full 4-6 foot height tithonia is grown for. Compact types like 'Fiesta del Sol' top out around 3 feet, a different plant for a spot that wants a low border, not a late-season screen or a tall cutting flower. (source)
- 'Fiesta del Sol': A 2000 AAS winner Clemson describes as maturing at about 3 feet, bright orange with yellow centers, well suited to smaller gardens where Torch's 4-6 feet would overwhelm the space. (source)
- 'Goldfinger': The smallest of the three per Clemson, orange-gold flowers on a 2-2.5 foot plant, an even more compact option than Fiesta del Sol for the tightest spaces. (source) Buy seeds: True Leaf Market
Why each variety is listed comes from the source shown next to it. We haven't grown these ourselves yet, so treat this as a research-backed starting point, not a personal endorsement. The buy links are separate from those sources: they go to seed suppliers that sell that exact variety, and we may earn a commission on some of them.
Where to buy tithonia seeds
True Leaf Market · Burpee (each supplier's tithonia seeds)
The varieties we recommend above each have their own buy links, for the suppliers that sell that exact variety.
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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)
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Growing Tithonia (Mexican Sunflower): A vigorous, heat-loving Mexican sunflower that provides a late-season burst of butterfly-friendly color.
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