Tithonia (Mexican Sunflower) in Zone 3a & 3b

Tithonia rotundifolia

When to plant tithonia (mexican sunflower) in zone 3b

Zones 3a and 3b 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.

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 3's season

Zone 3b's frost-free window runs about 98 days, from May 30 to September 5. 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

• Botanical Interests
• True Leaf Market
• Burpee
• High Mowing Organic Seeds

See why we recommend these suppliers →

As an Amazon Associate we earn from qualifying purchases. Some links on this page also go to other retailers we may earn a commission from as an affiliate, at no extra cost to you. We only recommend products with a genuine consensus of positive, independent reviews. See the sources cited on each item.

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 3b calendar · Full companion planting guide · Full plant profile · Plan your beds in the Garden Designer →

Pin this for later

Growing Tithonia (Mexican Sunflower) in USDA zone 3b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.

Save to Pinterest