Question About Invasive (Mexican Petunia)

A while back I bought a bunch of plants that appear to be these at a yard sale without really understanding what they were. Now I find out they may be invasive in Florida. Should I dig them up and toss them?

I read that there are noninvasive and invasive types. Is that the case, and if so, how do I know which I have? I am confused.

I hate to dig these up and toss them, but I don't want to grow something that could harm native species. Other than being invasive, it seems like a great plant.

Thanks.

Cindy

This message was edited Jan 15, 2006 12:53 PM

I had Mexican Petunias. I loved them because they were so easy to care for and always bloomed. The flowers fell off at night, but they were full of flowers again the next day. They weren't the taller variety that I think is called Mexican Blue Bells. I trimmed them back, but they died. (probably because I didn't know that shears should be cleaned first) I plan to get more. I didn't find them to be invasive at all.

fireant, I think these are the tall type. I know they must send out runners because they were dug out of an overrun bed, but I could deal with runners. I don't know if they send out seed too. I was reading that some do not produce seed. I just have no clue. I guess I will call the extension and ask them if there is any way to tell.

Cindy

I have Mexican petunias, and I just whack them back when I think they get leggy. I kind of mound them when I clip them. I never water them or do anything to them. Not any big problem. They are lovely, and they are the favorite of one of my grown children.

Nina

I had a shorter kind, but mine were like Nina's as far as care was concerned. If I had not cut them, they would probably still be there.

the short kind always seemed to eventually die out on me but the tall will stay forever. they do seed and make a loud popping sound when they shoot the seed out. yes, they are invasive, but they are a welcome addition to my garden as long as i put them in a place where i can mow around them. sometimes they are the only thing blooming and are so reliable.

I have the taller ones and so far, no problem. They have bloomed but haven't set seed yet.
I've had mine about a year or so.

I think I'll try the tall kind next time. They are good bloomers.

I have both the tall (blue/lavendar colored) and dwarf varieties (white and pink). The tall ones do spread by seed, but not to the point where I would call them "invasive." I move the seedlings around to where I want them when I find them coming up where I don't want them. The dwarf variety (about 1 ft tall) seem to stay put without spreading. I wouldn't mind them being a bit more like their tall cousins. I have 1/2 acre to fill and the more the merrier of all my plants is my attitude.

We do have a Florida native "petunia" in the same genus (Ruellia). It is a low-growing variety named Ruellia caroliniensis. I sometimes find it springing up as a volunteer in my yard and it sometimes can come in as a "hitchhiker" with a potted plant from a nursery. So, if you like Ruellias, but have an ethical dilemma about possibly forcing out native species, you can grow the Ruellia caroliniensis with no guilt! LOL You can probably find R. caroliniensis seeds from some of the native plant seed suppliers online.

Jeremy

I have both the tall purple and the tall pink......the pink tend to spread by seed, and quite often (the seed pod dries, splits, and spills billions of little seeds) and my purple tall ones, spread by runners instead. I just hack back the purple ones at the end of the season, prune a wandering branch here and there, and they seem to be no big deal.....roots come out of the leaf joints, so quite often I just plant the trimmings elsewhere. The seedier pink ones DO cause quite a number of unwanted seedlings, but they are also very easy to weed out. I have been collecting the seed-heads to share, instead of letting them just drop everywhere.

Thanks for all of your responses. I feel better knowing I'm not the only one who has the plant growing. :-)

I also called the Extension today. The plant is listed as an invasive on at least one list but not on others (at least not yet). I was told that the Botanical Gardens has removed their tall plants because the property adjoins a natural area to which the plants could spread.

Because I am not located very close to any natural area, my plants probably would not present a danger where they are, and I was told I could probably keep them without doing harm or replace them with less invasive species as I wish. It was suggested, though, that I not give seeds or cuttings to anyone in areas where they are listed as invasive (north and central Florida - however, according to the one list, in south Florida, homeowners are just asked to keep them under control).

Also it was pointed out that the plants have some good qualities, such as providing food for butterflies. So in my environment, they might even be beneficial, at least better than nothing.

Cindy

I have the tall purple (Mexican Petunia) as well as the low red ruellia (Brazilian Petunia), that Jeremy mentioned. So far, I haven't found either to be invasive. What I have found is a harsh frost will zap them. I cut 'em back to live stem in the spring and they come right back. I don't know how they could be invasive up here because one freeze will really knock 'em back, but whatever. I tend to explain these things very carefully when someone wants to trade for something invasive -- just let people know what they're getting themselves into and then allow people to be responsible enough to police themselves and their own gardens. We're all grown ups here.

I like 'em because the flutterbies and hummers LOVE them. Both varieties.

It's hard to control them as an invasive species when they sell them at every Lowes, Home Depot, and WalMart.....so I don't think a few seeds for trade will do anything more than mass sellings of them. I also don't see them choking out other plants for space, or killing them off like vining plants with tendrils. So I really just don't see them as all that invasive, no more so than any other flower that throws seed....

I knew I had seen plants like these at Home Depot so I was surprised to find out when I found them in the database on this site someone said they were on that list. I did a Web search then, and sure enough they were.

At any rate, if mine get out of hand, what I plan to do is cut them with a dirty pair of shears like fireant did. If it works on my plants too, then I'll be able to tell all the invasive plant experts how to get rid of them. :-)

Cindy

I have to get in on this one. Down here it seems to be the opposite of what you in the central and northern regions experience.

I have had both, and still have both though not by choice. I pulled out the taller violet and pink one's over three years ago and they are still coming back everywhere I planted them. I can even dig them out and more come back very close to the same spot.

The smaller one's I have in White, Pink, and Violet don't spread by roots but they do spread by seeds. Even though they grow everywhere, but in the grass, they easily pull out and don't reappear.

Both are very easy to grow and require nothing special to grow. They like full sun or full shade and anything in between.

You can grow the large one's by simply cutting a single branch into a bunch of little pieces and planting the pieces in the ground. Try to save pieces between the joints for planting. The smaller one's you cut off the tops and plant them.

They are classified EPPC1 Source - Florida Exotic Pest Plant Council's 1999 List of Florida's Most Invasive Species Category I - Species that are invading and disrupting native plant communities in Florida. This definition does not rely on the economic severity or geographic range of the problem, but on the documented ecological damage caused.

Art

Very interesting news, Art. I will watch my Ruellias carefully, but I think in our frost prone area, they are more likely to not spread so profusely. I notice in the DG Plant Files that there are about 50 Ruellias. Does the Most Invasive Plant List say which specific species are invasive?

Dzilla. The low-growing bright red "Brazilian Petunia" we both have is Ruellia elegans. It is different from our Florida native plant, Ruellia caroliniensis. I've not found the Ruellia elegans at all invasive. I would love for it to spread more! I saw hummers feeding from my R. elegans plants this past summer!

And you can't tell from what is sold at Home Depot and other mega-garden centers as to whether a plant is invasive or not. I was amazed at one of my visits to a Home Depot garden shop to see 3 gallon containers of Golden Rain Tree (Koelreutria paniculata) for sale! Talk about invasive! I have about 1,000 of their seedlings in my yard at any one time! But I guess someone must be buying them or they wouldn't be available.

Jeremy

Art,

The list doesn't have it as category 1 in South Florida. It is only cat 2. I guess that means they haven't documented the same ecological damage. That seems odd since it sounds like this plant spreads better there than in the north part of the state.

Jeremy,

There are only two I see on the list, and only one of those is a cat 1 invasive - the one that I have. I don't see your Brazilian petunia on the list at all. Here is a link to the list alphabetized by genus:

http://plants.ifas.ufl.edu/concl_genus.pdf

Oh, wow, I just found a database that says where and when each plant is reported as invasive as well as who reported it. It was reported at three sites here in Pinellas in 2003. I see it was reported in Lee and Collier. Isn't that considered South Florida?

The database is here:

http://www.fleppc.org/query.asp

Cindy

Invasive or not, I am wondering where you all got white ones!! I'd love some!
I have a fenceline of purple....and my pink ones in large urns, so I guess they are somewhat controlled.
:)
MerryMary

I've never seen any color other than purple. I am getting more this year because they are carefree plants. It's when I tried to take care of them that they died. I did cut them back right before a frost, though. That may have been a factor. Now I wait until the end of February to prune anything.

Fireant, I can mail you some seeds for the pink.....send me a DMail if you want some. Scatter them and they WILL grow, no effort needed....
MerryMary

Ok, thanks, Mary.

The Ruellia I have I can't be sure of the correct name or genus. I call the small one Mexican Petunia and the tall one Ruellia. I have had these plants for many years. Often in our travels to various garden area's, our SF Galloping Gardeners have seen them in places we thought we would never see them, for example Fairchild Tropical Gardens, where we saw the tall one's. The following information on these var's came from the USF plantatlas data base.

Ruellia brittoniana syn. tweediana, Britton's Wild Petunia, Mexican Bluebell is class Class 1 invasive. Here on Dave's, it's shown as tweediana on the fourth page of the Ruellia pages. Also on Dave's it's shown as brittoniana on the first page of Ruellia. Here is the link showing the synonyms at the USF plantatlas data base.
http://plantatlas.usf.edu/synonyms.asp?plantID=1302

Art

Mary, I will send up some white one's with the other stuff on Monday.

I only have the dwarf white ones, and I haven't found a species name for them yet in the DG Plant Files. I'll need to do some research on that unless someone else knows their I.D. From Art's info, it sounds like only the tall (usually purple type) R. brittoniana are invasive. I wonder if there is a bird that eats their seeds or if they are spread just by underground root systems as some have reported here or by wind blown seeds? My R. brittoniana only seem to reseed themselves within a yard or two of the original plant, and then only one or two seedlings, but I suppose, over time, the progressive march of the plants throughout the seasons could crowd out some native plants in the wild.

Jeremy

Here's a whole page of different ones.

http://www.plantdelights.com/Catalog/Fall/page58.html

Cindy

Thanks, CindyD. It was really interesting to see the hybrid cross of the native R. carolinienses and the Mexican R. brittoniana. A very weird offspring!

Jeremy

When I moved to the last place in Lauderdale, I took a bunch of cuttings of the tall purple ones and planted them by my patio. It was a surprise to me when one bloomed pink. I have never had a pink tall one so I called it a sport.

When I moved all those plants from Riverland, evidently there were seeds in the soil. Throughout the year I saw Ruellias, the tall ones, popping up in my cannas, daylilies and perennial beds.

I don't have any right now but hope to get some to plant on the front edge by the road. I have to wait till the weather is consistently warmer here.

Molly
:^)))

Mine are in a pot. They are attractors for butterflies and hummers.
I haven't found any volunteers yet. They sell em at every nursery, so if you like em let em grow and just keep an eye on them.
Sidney