PlantFiles: Asiatic Dayflower, Blue Dayflower
Commelina communis

I find the blue pigment to be very stable and long-lasting. I collected many petals into a small container of rubbing alcohol and have used it like water-color. The pigment turns green when an alkali (like baking soda) is added.

My great aunt grew these around her shady porch & gave me a few cuttings 40 years ago. It hasn't been too bad, I just pull up the volunteers that come up where I don't want them. Pretty easy to pull when they are small. I love the pretty little blue flowers. When it is finished blooming, I pull all the plants (not much to look at without flowers) & they come back again the next year.

This plant is gorgeous in early to mid Summer! It does not spead as much as you would think after reading some of these notes on this plant. The flowers only last from 10:00-1:00 in the height of bloom. They are the most pleasing shade of Blue ing my Gardens!

Pretty in bloom, yes, ugly plant, yes. But just start in spring and pull an it won't really be all that bad.

Invasive as they get--one of my biggest pests!

As others have noted, it's quite invasive here in Massachusetts, especially in moister areas. Admittedly the flowers are quite pretty, but the plant grows gangly later in summer and crowds out all competition.

I just found out what this was after having it around for a couple of years. I really don't have a problem with them as I find I can eradicate them just by pulling them out of the areas I want to clear. My soil is very sandy, maybe that helps. They have the truest blue flower, which is probably their only saving grace combined with the fact they attract pollinators and song birds. They can however multiply faster than rabbits and have to be kept in check. I keep them around in areas I am not working on...better than having something else take over which is harder to get rid of!

I am shocked anyone would want this near their yard-it is a very invasive weed at my house....every time I pull it-it comes back double! You can have all you want-just e-mail me!

This is a very tough and very fast-growing annual with prodigious self-seeding ability. When it gets tall enough that its weight starts tipping it over, it puts down roots from the stem to help it spread sideways.

It grows in full shade and full sun. It can handle flood and drought. It makes a great groundcover, especially in shady areas. It has brilliant blue flowers with a touch of yellow in the center.

Although it can become invasive over a single season, it dies off every winter. It also has a shallow root system. With consistent weeding you can control it, if not eliminate it. The seeds can apparently lie dormant for years, if not decades. When I pulled up the landscaping fabric that had covered most of my yard for years, the next spring every square inch of the yard sprouted Asiatic Dayflower.

I think it's pretty, and I let it grow where I don't have anything better to plant yet. If it starts invading my other plants' space, it just takes a few minutes to rip it out by the handful.

I finally have a name for this little beastie. I called it Hitler-weed because it invaded everything around it. I'll be pulling this til the day I die. Once established just try to get rid of it. I dare you. This plant was running rampant through my garden when I bought my home. Little did I know after pulling sixty pounds of it (two 55 gallon trash cans) that it would gleefully reappear en masse the following spring. It took Roundup in stride. Does anyone know where I could find some left-over agent orange?

The flowers are pretty, if tiny, and the foliage is nice until summer heat shrivels the leaves and makes the stems leggy, but at least in my area, with temperate climate, modest rains, and average soils this is a plant for garden masochists or enemies. Toss a handful into an out-of-the-way spot of a garden that belongs to someone you don't like: they'll have decades of annoyance.

Just remember that karma can be awful.

Edit:

Asiatic Dayflower is known to be Round-Up (glycophosphate) resistant. Herbicides containing flumioxazin are recommended to kill dayflower infestations. Flumioxazin is marketed by Valent Professional Products as Sureguard and Broadstar, although I like the idea of dropping the little shoots in butter and watching them wilt.

I really do not like this plant.

This plant is a superweed, much like the weed oxalis, which will grow anywhere except standing water. Asiatic day flower will grows even in dry shade and dry sunny location, of course, in a smaller form that is slightly less invasive at maybe three to four inches in height. In rich soil with a bit of shade (for me), Asiatic day flower flowers more readiable and grows from one to three feet tall. ( I had a wire fence nearby, so that account for the three feet tall plants). The day flowers are a pain to remove because they can become entangled in my daylilies and the fence, making it difficult to remove all parts of them. They even thrive in my sandy soil! It's a pity no one have developed a clumpy sterile form of this as rich blue flowers are a rarity. I suspect their seeds have a long dormancy so whenever you churn up the soil ie weeding the adult plants, they germinate the next year. Also it might be the most cold hardiness of day flowers, as I have not seen the other species around here. I think I got it from my grandma, which is in zone 3b!

Known here a Asiatic Dayflower, it is extremely invasive; but at least it is edible. The young leaves and stems can be added to salads or boiled for 10 minutes and served with butter.

The genus name of this plant was actually named after three members of the Commelin family. As indicated in the definition provided above in the genus info, it was named for Jan and Kaspar Commelin. However, Linnaeus named this particular genus Commelinas for three members of this Dutch family. The flower of a related species, Commelina erecta, has three petals, two conspicuous blue ones, and one small white one. The two blue petals are meant to represent Jan and Kaspar Commelin, both prominent botanists. The smaller white (blue in the case of C. communis) petal represents another Commelin botanist who died before he was able to contribute anything of import to botany.

The blue flowers on this weed are pretty but it's so invasive and healthy, it ends up spreading everywhere. I thought it was pretty one year so let it go, that was a big mistake! Now I fight it all the time. One good thing about it is that it pulls very easily. Just don't leave the plants you pull lying around, they will start to grow again!

There are several very like flowers of this species. There is one rather rare form that has 3 petals. There is also a 2 petaled species that has much larger blooms than the more common tiny one. Both of those once grew here on taller more upright plants. I assume mowing may have caused their demise. This was once all pastureland when they were plentiful.

The plant with the tiny blooms still lives and invades the garden wherever possible. I have collected 2 plants into pots and found they are perennial. They are in their 4th year in the pots. I love the blue color. If only I had known the larger plants could be lost I would have collected them to preserve.

I believe the 2 photos posted by noxiousweed on this page may be incorrect.
According to my information the genus Commelina has unequal petals (one distinctly smaller and often different colored than the other 2).
MotherNature4

I know it's invasive, but I love the electric blue flowers. It's not been hard to control; since it's shallow rooted, I just pull out clumps when I want to stem its spread.

I live in Wisconsin. I first found this plant growing at my grandmother's farm when i was about 4yrs old. My grandmother couldn't remember anything about it at the time. Well last summer i brought some iris's home and incedentally brought a little bit of it home too. At first we pulled it out, but it always came back. Now this year it has covered an area of about 8 square feet in 1 season. I find it a very attrative plant and very good ground cover if you dont like pulling weeds. Of course if you dont keep the DayFlower itself in check it will kill off other small plants such as Lily of the Valley.

I found this plant growing wild in Cuba, and found it grows easily from seed, flowering in a few months. It is very pretty in flower, having a pure blue colour not often seen in flowers and looking like tiny butterflies.
Downside? --- The flowers only last in perfection for about an hour! If anyone has any clones which last longer (even a full day) it would make a more desirable plant.
It grows easily in a small pot or open ground, any soil.
Easily controllable outside here in UK.

This plant grows along our fence, and makes a very attractive border for the yard, and the flowers are small, but very bright and pretty. It has stayed restricted to the fence line, and we have never had any problems with it. I enjoy this plant.

Though blossoms are quite blue, they are very tiny. Of course as stated they last only a day. Plant is pretty invasive, although true blue, because of invasiveness and size of the flower I wouldn't recommend this as a garden plant...........

Asiatic Dayflower appeared spontaneously in my yard in Los Angeles, California, USA some years ago. While it is certainly invasive, I have found it simple to control, and I truly enjoy the lovely electric blue flowers on that lush green background. It grows with two other "weeds", yellow and red wood sorrel, along with fern beneath a 40 year old Sequoia, I derive as much pleasure from it as from my "formal" roses, etc.

I kept pulling it out before it would bloom and go to seed and it kept coming back. The blue is a nice color and uncommon in flowers, though. That helps me live with it, as getting rid of it was just an exercise in futility.

Several years ago I received this plant as a "bonus" within the pot of another end-of-season purchased perennial. This is VERY invasive, even in my USDA Zone 5a garden. If it's anywhere near moist soil conditions, it is a very aggressive stoloniferous plant. It took 2 years of aggressive "weeding" to get rid of (almost) all of it. I expect I will once again find some with this spring growing season.

It's just a subtropical weed, but it has very attractive blue flowers; the picture Vince submitted on 12/14/2002 has the real colour, but it's so much smaller in reality. The flowers last only a day, and afterwards each fruit contains 1 or 2 brown seeds, oblong and dented all-over, about 2-3 mm long.

I found the plant in the garden of hotel "Neptun" in Dubrovnik (Croatia) in 1983. No idea if the hotel survived the war in the 90's, but I suppose the plant did. It grew among Oleanders and other subtropical garden plants, creeping on the ground, an unsignificant weed. But these truly blue flowers drew my attention, I took a cutting home, and grew it for years in my garden in the Netherlands. I suppose it was an annual, but it sowed itself. It thrived at first, but after a few really cold winters it disappeared.

January 1, 2004
About a year ago I wrote the above story.
Last summer it was extremely hot and dry, unusual for the Netherlands. I was very surprised to see the Blue Dayflower again in my garden after an absence of about 6 or 7 years. Just one plant, showing up around June. I sent in a photo, so you can see.
I wonder if the seeds can wait long till they germinate, or if the plant has come back there every summer but hidden under other, bigger plants. I had cleared that bit of ground because the shrubs standing there weren't too good anymore.
Perhaps it survived this time because of the drought - there weren't as many snails and slugs around as in other years, and those are fond of this plant.

Although this plant is closely related to its more well-behaved cousins the Tradescantia (Spiderwort) plants, it is considered an invasive weed by most gardeners, with few redeeming qualities. Its blue flowers are arguably this plant's best feature, but are small unless viewed upclose.

As its common name suggests, the plant was introduced in Asia, and the flowers last but a day. However, repeat blooms keep it blooming for many weeks in mid-summer.

Grow with extreme caution, as it will quickly spread in a cultivated setting.