Mexican petunia carries purple, five-lobed funnel flowers above narrow, willow-like green leaves on upright green-to-purple stems. The blooms continue through summer and fall, and butterflies and hummingbirds visit them. Mature plants commonly form vigorous colonies about 60 to 120 centimeters tall and 60 to 90 centimeters wide.
Grow it in full sun for the heaviest flowering or in partial shade. Fertile soil can range from well drained and evenly moist to boggy or occasionally wet, while established plants also tolerate drought, heat, and humidity. Cut stems back after flowering to encourage fresh bloom.
The straight species spreads by rhizomes and seed and can be difficult to remove once established. Check local invasive-plant guidance before planting; it is invasive and not recommended for use in Florida. Where it is permitted, keep it contained and monitor for unwanted rhizomes and seedlings.
