PlantFiles: Flower Of An Hour, Venice Mallow
Hibiscus trionum

As an avid gardener (veggies and flowers) I have fought for years to YANK these out of my gardens where my veggies grow. I guess I never notice it anywhere else in the yard and or flower gardens. But this can and will take over, but a good tiller w/plenty of horse power keeps the buggers from even getting more than a few leaves on.

The pictures on here are far more prettier than in person, and I never took much notice of how long the bloom was for. I just know it preferred to grow where I didn't want it.

Quasy in S.E. Iowa

I have never seen this plant before this summer. We brought home a truck-load of dirt to do some landscaping and I believe that this seed was brought to our yard through the black dirt we laid. It has only started to grow where we laid the new dirt.

Before they started to bloom, I was pulling them out of the yard but I got a little behind on the weeding and found a few flowering one morning. I had no idea what they were but I thought they were pretty so I left them. They bloom in the morning hours at different times, it seems it is dependent upon how much light is hitting them - all of them are closed by noon.

I am planning on making a native species wildflower garden in the spring so I am going to leave a few of them but just control their growth by pulling up the new plants. I think as long as I mix longer blooming flowers that grow at the same height - the weedy look they get after the flowers close will not be a large issue.

Thanks for all the other opinions!

I can't believe this weed is even listed here. It is terrible! The only good is when soybean aphids arrive, it is the first plant they attack. Then when you are pulling them, you get nice sticky goo all over you!

It will chock out your good plants.

Indigenous to Europe, Flower Of An Hour loves disturbed areas and flourishes in them. This plant will probably end up on noxious weed lists sooner or later at the rate I'm seeing them pop up here there and everywhere. The flowers aren't even that showy and they aren't open all that long. Perhaps around a half hour early in the morning and after that all you get to see is scraggly foliage sprawled out over the ground. Good thing is that it is an annual so if you keep pulling it up, sooner or later you'll beat back the seed bank.

I'm with JEFE. I had never seen this plant until after we had our sewer line put in. I must admit I think the flower is beautiful, I have seen many of them bloom, each time I made a mental note and tried to find out what it was. After 4 years I found it on the internet with many warnings, it is an invasive weed. The seeds came be dormant for 50 years the are where these started to grow had not been touched in 23 years so crunch those numbers. All it took was the rain and a little sun and they invaded like Atilla the Hun. I just found out they were a weed today but I sort of knew that several years ago when they came out like gangbusters. The flowers bloom quickly but the seeds grow and spread quicker. The name is Venice Mallow (Flower of an hour) (Hibiscus trionum) I found the info on Weedalert.com.
This plant needs to be tacked up on the Post Office Bulletin Board. Another good thing I can say on the plants behalf is, the tap root is easy to pull out. I'm sorry to burst your bubble about this pretty little flower but I like to personally choose the plants for my flower beds, I must admit I let a few grow but when I couldn't keep up with the seed production I started the evacuation process which is still going on after 4 years.
I feel better now. Thanks for the chance to get that off my chest.

One plant came up in my garden outside of Philadelphia, PA this summer and it has taken weeks for me to identify it. Maybe it will become the invasive problem that others write about, but this beautiful flower is a joy the few hours it comes out.

I have a tough time considering Canada Thistle as a weed. However, Flower Of An Hour, Venice Mallow Hibiscus trionum is a WEED. It is not just invasive in our garden it is EVIL, bad, malo, muy malo, inicuo.

Before I identified this weed and knew what it was, I have literally checked every half hour looking for blooms. Thinking it was some really cool, rare plant. Oh! You Venitian Vixen you fooled me. Flower of an hour? Try flower of a second! Some days it never bloomed.

Kill them early and kill them often would be my suggestion. When you think of this plant, think INVASIVE, such as in "Invasion of the Body Snatchers".

(Sorry for the SHOUTING. I am just trying to warn you.)

I love this flower. We have it wild here in SE Ohio. One year it came up in one of my flowerbeds and I've left it reseed year after year.

Bladder Hibiscus or Flower of the Hour.
Found in Asia Africa and all Australia.
Good bedding plant slightly upright trailing habit.
I purchased a single 3" potted plant from an organic herb farm over 4 years ago . The sales lady told me it would probably only survive as an annal.This annual-biennial is very hardy, tolerates dry heat. Self sows and can become invasive if you do not remove seed pods and or new seedlings in your garden.
They are the most beautiful flower, Creamy petals with an almost black/violet center.
It will take your breath away!

We bought seeds for this plant in New Zealand and it has grown over two meters high! As of September 2003, it's still pushing and flowering.
Henk Maters

Plant self-sows prodigously and apparently the seeds can survive in the ground for many years, waiting for the correct conditions to germinate.

Flowers only remain open for a few minutes, closing as soon as clouds or shade strike them.