Ageratum means floss flower.
These fluffy flowers fill up the gap when you are looking for a rare colour among flowers.
They are not only beautiful but also have a very long flowering time that lasts for months and months from spring to late autumn and in warmer climates through the whole year. These characteristics make them ideal for your purple flower garden designs and purple flower landscaping. Ageratum cannot tolerate frost and cold temperatures.
You can grow them from seeds or buy them from nurseries.
When the flowers turn yellow, get a plastic bag and collect the seeds and then pinch off the dead flowers, this will encourage more flowering
They need regular watering and full sun, however, will do fine in part shade as well. If they do not get enough sun though they get diseased with fungal issues such as powdery mildew. If that happens remove them from shade and place them where they get more sun exposure. You can cut the affected part and let the plant re-generate new leaves.
Make sure the soil drains well and is rich. Fertilize the soil every few months with a balanced organic fertilizer. Ageratums are heavy feeders. When you see them showing yellow leaves they are telling you they need more food and you have to fertilize them.
To suppress weeds place a layer of mulch and retain moisture. Ageratums do not like to dry out. Watch this video to learn more about Ageratum.