Ageratum, sometimes called ‘floss flower,” derives its name from the Greek words meaning “not old.” One of the explanations for the name may be that these plants are such prolific bloomers and are able to retain their color and fresh appearance for a long time, seeming never to age.
The flowers appear at the ends of short stems and are dense clusters of puffy, button-shaped blossoms. Ageratum is available in two sizes. Low-growing varieties, which form a neat mound, are perfect to edge beds.
Taller ageratum can grow up to 24 to 34 inches high can be grown from seeds and make nice cut flowers. Although ageratum is best known for its blue or lavender flowers, it also comes in pink and white varieties and looks best when planted in clusters.
Locate the planting in full sun. Add plenty of organic matter to sandy soil. To prevent root rot problem, be sure not to plant too deeply. The plant needs frequent watering for the next few weeks. In sandy soils daily watering may be needed.
Ageratum is deer resistant, but it stops blooming in high temperatures and damp rainy weather. If you remove deadheads, it will rebloom when the weather cools.