Last updated on November 20th, 2025 at 01:03 pm
Ageratum Plant – Also known as whiteweed and floss flower. It is a big family of plants that has over 60 species. They are considered annual plants in regions where there are consistent freezes. It is a good plant to use in containers surrounded by other taller plants. You can also place it in your flowering garden, but it should be used as a filler plant as it does not grow very tall, about 4, maybe 8 inches in height.
The Ageratum plant is pretty common in the Southwest, and you’ll notice it for its soft, round blooms that almost look fluffy. The flowers have a cool blue color that stands out in gardens and makes them easy to spot. They usually start blooming in the middle of spring and keep going until fall. If you want the best results, you should plant them in early spring, right after the last frost. Some people say you could plant them later, but then you might miss out on how many flowers you get. When you see those blue blooms, it really feels like spring and summer are in full swing.
Images of the Ageratum Plant
The flower of the Ageratum
Common Ageratum
The most common Ageratum Plant is the blue variety. Most retail nurseries will have this plant during the early spring season. Plant them in mass for a great blue wave of flowers. They’re also taller types of this plant; however, it is rare you will find them in nursery or greenhouse retail stores. The common plants are short and should be planted in front of other taller perennials or annuals. They can take full sun or partial shade. Keep them well watered, making sure your soil drains well.
Hybrids of this plant
There are many hybrids of this plant, and they come in white, blu,e pink, and purple. You can read more about the hybrids of this plant over at wimastergardener.org.
When the flowers stop blooming, they will turn a brownish color. Deadhead these expired blooms for a new explosion of blue flowers.
Ageratum plant long lasting flowers
Taller Coreopsis flowering perennial plant with Blue Ageratum in front.
Problems with this plant
Ageratum is a hardy plant and not susceptible to insects or diseases On occasion, they might get spider mites, but it is rare. Spray with some neem oil to remove insects. Neem oil is an organic spray. Try spraying often; this will kill these insect pests and help with mildew-type diseases. Read more about insect diseases on plants.
The Ageratum plant is toxic to dogs and cats, according to ASPCA.ORG
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thank you guzmansgreenhouse for giving me wonderful information
Thanks, Rohit we strive to give our subscribers and visitors the best gardening information available online.