Ageratum corymbosum, commonly known as perennial ageratum or blue mistflower, is a perennial herb native to the open woodlands and scrub areas of Mexico and Central America. It typically grows to a height of 2-3 feet (0.6-0.9 meters) and spreads to a similar width. The plant features fluffy, brush-like flower clusters that are usually a shade of blue or violet, blooming from late summer to fall. The flowers are highly attractive to butterflies and other pollinators, adding to the plant’s ornamental value.

Perennial ageratum is appreciated for its long blooming period and the vibrant color it adds to borders, butterfly gardens, and cottage gardens. It is relatively easy to maintain, requiring minimal care once established. The plant thrives in full sun to part shade and prefers moist, well-drained soils. While it can tolerate short periods of drought, regular watering promotes optimal growth and flowering. It is not commonly associated with serious diseases or pests, but powdery mildew can be a problem in humid conditions. Gardeners should be cautious about its potential to spread aggressively, particularly in regions with mild winters.CC BY-SA 4.0