Photo Courtesy of Proven Winners

Ageratum houstonianum 'Artist Blue'

Floss Flower

Ageratum is a popular filler choice. Whether in a potted combination or in your landscape, Artist Blue is complimentary to many flowers and has a very low pest risk. This hardy little plant needs a space of 10-12 inches to properly grow, as the height to be expected is 8 to 12 inches while the spread should be between 10 to 12 inches.

Ageratum features opposite cordate shaped leaves with a hairy texture and small fluffy flowers that provide a burst of color all summer long. Its ability to thrive in full heat and full sun make it a very good choice for hard to fill locations in container combinations, landscaping, and window boxes.

Ageratum Artist Blue provides a rare true blue to the floral world and has recieved several awards for its performance. It is a hardy, mounded, well-branching plant with good flower canopy and unique color quality.

Height: 8-12 Inches

Spread: 10-12 Inches

USDA Zone: 9 to 10

Color: True Blue

Interesting Notes:

While the majority of Ageratum species, family Asteraceae, are native to Central America and Mexico, a few are actually native to North America. Its environment of origin is one of tropical heat and warm temperatures. Ageratum thrives in full or part sun at a temperature safe from the threat of frost and is one of few annuals to tolerate light shade.

Artist Blue is a vegetative line produced by Proven Winners, which is more uniform and consistent in flowering than seed grown varieties. Ageratum is commonly called floss flower because of its small, uniquely textured, "fluffy" flowers, which burst forth from the end of each stem. This compact annual provides a very rare shade of true blue to the floral spectrum and is a great companion to many other plants in a garden landscape or potted arrangement.

Growing Tips for Homeowners:

As with every plant purchase, it is important to look for quality. When purchasing, be sure to avoid gangly looking plants. Healthy Ageratum should be compactly mounded and floriferous, with small 'button-like' flowers at each stem end. Finding a fresh young plant, without yellowing foliage or dying flowers is very important. Look for rich green foliage and small tight flowers as indication of the plants care thus far. This will ensure an easy start for you and a long life for your plant.

After locating and purchasing the perfect plant at the store, it is important to find a good home for it in your garden. Ageratum is a sun-lover, being a full to part sun plant and will thrive in any location without shade, but it is also one of the only annuals that can tolerate a bit of shade. Optimal sun time for the Ageratum is about 6 hours of sunlight each day.

Because of its tropical origin, Ageratum does not tolerate the cold. Be cautious not to plant it outside too early in the spring. If there is still a chance of frost in your area , keep your plants potted and safe indoors, maintaining care in the container. Once planted, Ageratum will last from late spring, through the summer, until the frost returns in the fall.

Artist Blue Ageratums are easy maintenance plants, which require regular watering and minimal foliage care. Fertilizer or compost application will ensure optimal plant performance. Be sure to apply low to the ground, near the plants stem, for quick absorption and utilization. It is important to ensure good drainage in both containers and landscaping. Lack of proper drainage can cause root rot, when the roots get soggy and become diseased. Drainage holes, elevated flower gardens, and proper soil composition are three great ways to prevent root rot and help your plants maintain a healthy moisture level.

Unlike other varieties of Ageratum, Artist Blue does not require deadheading, as the new flowers will cover the dead ones, although, removing old blooms will not harm the plant. If your plants start to look messy , feel free to trim them back to keep them tight. After pinching back, your plant should begin to bloom within 1-2 weeks.

Ageratum is susceptible to spider mites and whiteflies. Spider mites are usually found on the underside of the leaves but are very difficult to see without a magnifying glass. Indication of a spider mite will be damage to the leaves in the form of tiny pinholes. Whiteflies also tend to operate on the underside of the leaves. They look like tiny white moths but operate much like aphids. Damage to the plants will include yellowing, shriveling, and premature dropping of leaves.

The earliest prevention against disease and pest threat is careful examination during the purchasing process. If you suspect you have a pest problem, hang a sticky trap above the plant to catch the pest in order to get a clear diagnostic for optimal pest control. It is important to know the difference between harmful pests and beneficial insects. Some insects may lay their eggs on your plants leaves in order to feed on the pests, which is actually beneficial to your flower. Removal of the wrong eggs could promote pest survival and growth. Ageratums are attractive to pollinators, such as butterflies and hummingbirds, which add a touch of beauty to the garden while promoting plant growth.

Characteristics & Attributes:

Attracts Wildlife:

  • Hummingbirds
  • Butterflies


  • Heat Tolerant
  • Compact
  • No Deadheading

Critter Resistance:

  • Deer Resistant

Design Use:

  • Window Boxes
  • Rock Garden
  • Mass Planting
  • Filler
  • Edging
  • Container
  • Tropical
  • Border


  • Full Sun / Part Sun

Foliage Color:

  • Green


  • Mounding

Season of Interest (Flowering):

  • Spring
  • Fall
  • Summer

Season of Interest (Foliage):

  • Fall
  • Summer
  • Spring

Soil Moisture:

  • Well Drained
  • Average


  • Compact