PlantFiles: Floss Flower, Ageratum
Ageratum houstonianum

it may be invasive and has spread all over i love it because the butterflies love this plant. wish to keep it going. if you dont like invasive you definitely wont want this one.

This plant is a terror when it comes to staying where you want it. A neighbor 3 houses down from me planted it and the next year I had a yard full of it. I have been trying to kill it off for a few years now. More like a weed to me. Cant see why anyone would want this in their garden by choice.

While I have purchased this plant for borders in my garden at home (zip code 63301 - Zone 6a) and it has grown well with no problems of invasiveness, I had never found it growing in the wild before. We found this plant growing wild on our property next to the river (zip code 63625 - Zone 6b). It was growing both in the shade and in a partially sunny area. The areas were fairly wet with rich soil, and the plants seemed to be approximately six inches in height, good blooms, and good leaves. I will be anxiously waiting to see if they come up again next year.

Sometimes people confuse Eupatorium coelostinum (mistflower) with this plant. I suspect it developed from it. E coelostinum is defintely beatiful but a bear to deal with in a flowerbed with other plants. Extemely invasive with extensive white rhizomes.
For those who found it growing in their yards it is probably this plant as oppsed to A. houstonianum. Both reseed everywhere. I let one grow for a year because my wife liked it and that was 5 years ago and I'm not rid of it yet and I suspect I never will be.

I kept finding these cute fluffy little blue flowers popping up in various nooks and crannies around the yard, not in actual flower beds. Thought they were "weeds", even pulled a few, but kept finding myself attracted to the flowers. Don't know where they came from. I did sow some wildflower mixes last spring. This plant is not on the list, but may be one of those listed on the package as "others". Anyhow, considering that they are growing in uncultivated soil and apparently as a result of seeds broadcast elsewhere and washed about by rain, they must be pretty easy to grow from seed.

This plant was growing in semi-shade in one area of my yard when I bought my house three years ago. I assumed it was a wildflower, but I can't find any reference to Ageratums in my field guides, so it may be a remainder from some previous gardener at my property or a self-seeded stray.

I greatly enjoyed the blue tufts of flowers in Autumn when most other plants had ceased blooming. My A. houstonianums are most similar to the first photo in the pixs for this plant on this page, except that they are closer to a "true" blue, which seems to be a color hard to find in plants.

I made a decision to devote the area completely to liriope where the Ageratum was growing. I enjoyed the plant so much that I decided to move it to some other locations and provide it with more sun. That was somewhat of a mistake. It responded to my kindness by multiplying 1,000 fold! It was nice to have a huge patch of blue in my blue/white garden last Fall, but it reseeded and also spread by its shallow underground root system to cover much of that garden plot as well as much of the other area where I moved it.

IF YOU WANT THIS PLANT, just let me know you are willing to pay postage and I will send you a bare root BOX full of it! I need to pull up most of it before it spreads further, but I hate to destroy it as it is so attractive when in bloom. It seems to survive bare root transplanting without much stress. I am sure I will have plenty of new seedlings each Spring for years to come.

A welcome sight every autumn...the fields have a cheerful look with these beautiful little flowers.

Cattle won't graze them, so they dot the landscape each fall.

Spreads by underground runners and by seeds...easy and carefree, few pests. A great plant for a natural garden

I live in the Southern Interior of British Columbia and found the the Hawaii Shell Pink Agertum plants that I grew in a South exposure flower bed did extremely well. Grew quickly into lovely bushy plants with lots of purple/pink blooms.

My experience with Ageratum has been very positive. This year I've used several plants in my window boxes and have been extremely pleased with their color and behavior. I've also learned that they are easily rooted by pinning a longish stem to the soil next to the parent plant. In a couple of weeks, I had a plant that was ready to be separated and potted in a new location.

My next experiment is to see if I can keep a few of my plants alive, since this variety is not available every year. Right now I'm planning on keeping it in a windowsill until I have a lighted system for my plants.

Self seeded agerata may be considerably taller than store purchased plants. 24" or more

Half-Hardy Annual. Fluffy flower clusters bloom all summer on these compact plants. Don't cover your seeds; they need light to germinate. Floss Flower is an effective selection for your border or as an edging. The soft blue flowers are an excellent accent for other flowering border plants or foliage plants. They will benefit from a monthly fertilizing. Deadhead faded blooms to encourage new flowering. Start seeds indoors at 70-75 degrees F and set out your transplants after all danger of frost. May be grown in partial shade; this is recommended for hot climates. 'Blue Blazer' and 'Blue Mink' are two tried and true varieties.