Mexican Sunflower (Tithonia diversifolia)
Mexican Sunflower (Tithonia diversifolia) is a bold, fast-growing plant known for its bright yellow to orange blooms and its value in low-input, pollinator-friendly landscapes. It delivers high impact with minimal fuss, making it a favorite for gardeners who want strong color and strong function.
From late summer into fall, the flowers provide steady nectar for bees, butterflies, and hummingbirds. In a food forest setting, it also earns its place as a “chop-and-drop” biomass plant, producing large amounts of leafy material that can be cut and used as on-site mulch to support soil health and moisture retention.
Because it can spread readily in warm climates, monitor and manage it carefully if it self-seeds in your area.
Any reference to medicinal or culinary use of plants or plant parts should in no way be considered an endorsement by The Ocala Food Forest or its staff. Research is crucial in safe and proper consumption or experimentational use of any plant.
Plant Information
| Scientific Name: | Tithonia diversifolia |
|---|---|
| Family Name: | Asteraceae |
| Common Name(s): | Mexican Sunflower, Tree Marigold |
| Size: | Up to 6–10 feet tall and 3–6 feet wide |
| Plant Type: | Shrub; perennial in tropical climates, annual in colder zones |
| Origin/Geographic Distribution: | Native to Mexico and Central America; naturalized in many warm regions |
| Native to: | Mexico, Central America |
| Native range in the USA: | Not native; cultivated and naturalized in warm areas (including parts of Florida and Hawaii) |
| Conservation Status: | Not listed as threatened; considered invasive in some areas |
Cultivation
| Planting: | Plant in spring after the last frost; direct sow in warm climates |
|---|---|
| Sun Exposure: | Full sun |
| Soil Type: | Prefers well-drained soil; tolerates a wide range, including poor soils |
| Soil pH: | 5.6 to 7.8 (slightly acidic to alkaline) |
| Water Requirements: | Moderate while establishing; drought-tolerant once established |
| Fertilizer Requirements: | Low; excessive fertilizer can reduce flowering. Use balanced slow-release sparingly if needed. |
| Pruning Requirements: | Prune to encourage branching and manage height; cut back for biomass as desired |
| Growth Rate: | Fast; can flower within months in warm conditions |
| Companion Planting: | Pairs well with drought-tolerant pollinator plants and as a support species in butterfly gardens |
Tolerance and Hardiness
| Drought Tolerance: | High once established |
|---|---|
| Frost Tolerance: | Low; damaged below 32°F (0°C). Grow as annual or protect during cold snaps. |
| Heat Tolerance: | Excellent; thrives in hot conditions well above 90°F (32°C) |
| Wind Tolerance: | Moderate; may need support in very windy sites |
| Salt Tolerance: | Moderate; coastal planting is possible with protection from direct salt spray |
| USDA Plant Hardiness Zones: | 9b–11 |
Flower and Fruit Information
| Fruit Type: | Insignificant; primarily grown for flowers and biomass |
|---|---|
| Harvest Time: | Not harvested for fruit; useful as chop-and-drop biomass during the growing season |
| Fruit Description: | N/A |
| Edible Plant: | No |
| Edible Parts: | None |
| Medicinal: | No significant medicinal uses reported |
| Flower Color: | Yellow to orange |
| Flower Shape: | Large, daisy-like |
| Fragrance: | None |
| Flower Bloom Time: | Late summer to fall |
| Bloom Duration: | Several weeks (often longer with warm weather) |
| Pollination: Self or Other? | Attracts bees, butterflies, and other pollinators |
Wildlife
| Attracts: | Bees, butterflies, and birds; hummingbirds may visit for nectar |
|---|---|
| Pollinators: | Bees, butterflies, and other nectar-seeking insects |
| Problematic Pest: | Generally resistant; occasional aphids and leaf miners |
Health and Safety
| Toxic: | No; generally considered safe around children and pets |
|---|---|
| Poisonous Parts of Plant: | None |
| Toxic to Humans: | Not toxic |
| Toxic to Animals: | Non-toxic; safe for wildlife and domestic animals |
| Plant Diseases to be aware of: | Occasional fungal issues, especially with high humidity and low airflow |
Companion Planting
In Florida planting zone 9, Mexican Sunflower companions work best when they support pollinators, add structure, and tolerate sun and heat. Use these plants to build a resilient, wildlife-friendly bed around your biomass and color producers.
Beautyberry (Callicarpa americana) — Florida Native
Benefits: Supports birds with berries and adds strong seasonal interest.
Use:
- Plant as a background shrub behind taller summer bloomers.
- Use to anchor a pollinator border with bird value.
Zone Range: 5–9
Firebush (Hamelia patens) — Florida Native
Benefits: Nectar-rich blooms attract hummingbirds and butterflies.
Use:
- Plant nearby for overlapping bloom windows and steady nectar.
- Use as a warm-climate backbone plant in wildlife gardens.
Zone Range: 8–11
Muhly Grass (Muhlenbergia capillaris) — Florida Native
Benefits: Adds texture and fall color; handles heat and sun well.
Use:
- Mass plant for a soft edge around taller flowering plants.
- Use to create movement and structure in sunny beds.
Zone Range: 6–11
Saw Palmetto (Serenoa repens) — Florida Native
Benefits: Durable groundcover with strong wildlife habitat value.
Use:
- Use as a low-maintenance anchor in open, sunny areas.
- Plant with spacing to maintain airflow around flowers.
Zone Range: 8–11
Coral Honeysuckle (Lonicera sempervirens) — Florida Native
Benefits: Red tubular blooms bring hummingbirds and add vertical interest.
Use:
- Train on a trellis/fence adjacent to pollinator beds.
- Use to add height without shading sun-loving plants.
Zone Range: 4–9
Pentas (Pentas lanceolata) — Florida Friendly
Benefits: Long bloom season; strong butterfly draw in full sun.
Use:
- Plant as a mid-layer nectar source in sunny borders.
- Stagger plantings for near-continuous blooms.
Zone Range: 9–11
Blue Porterweed (Stachytarpheta jamaicensis) — Florida Friendly
Benefits: Excellent nectar plant for butterflies and hummingbirds.
Use:
- Use as a color contrast in pollinator beds.
- Plant along edges for easy viewing and access.
Zone Range: 9–11
Gaillardia (Gaillardia pulchella) — Florida Friendly
Benefits: Heat-tolerant, long-blooming flowers that feed bees and butterflies.
Use:
- Plant in sunny, well-drained areas as a tough color layer.
- Use as a front border plant near taller summer bloomers.
Zone Range: 8–10
Tickseed (Coreopsis spp.) — Florida Friendly
Benefits: Bright blooms support pollinators; easy, cheerful filler plant.
Use:
- Mass plant for a wildflower look and strong nectar flow.
- Use to connect larger shrubs and tall bloomers visually.
Zone Range: 4–9