Jump to content

Menu

Why is purslane considered a noxious weed?


Recommended Posts

That's what is said about most non-native, non-commercial crops, isn't it? *shrug*

What native species is it crowding out?

Purslane is an indicator of poor soil health, as many weeds are. Is the problem the plant or the unhealthy soil?

Link to post
Share on other sites

It spreads super easily if tilled/broken up. AZ has a lot of slow growing desert plant species that cannot compete, some of which are required or important food sources for native animals. And it's a low nutrient soil naturally-not unhealthy, just that it isn't going to have the richness of a river Delta (for example). 

It's kind of like rabbits in Australia. They're cute, and edible, and some folks wanted them enough to bring them, but they totally out compete native species. 

Edited by dmmetler
  • Like 4
Link to post
Share on other sites
35 minutes ago, dmmetler said:

It spreads super easily if tilled/broken up. AZ has a lot of slow growing desert plant species that cannot compete, some of which are required or important food sources for native animals. And it's a low nutrient soil naturally-not unhealthy, just that it isn't going to have the richness of a river Delta (for example). 

It's kind of like rabbits in Australia. They're cute, and edible, and some folks wanted them enough to bring them, but they totally out compete native species. 

 

Purslane likes high phosphorus, I was just reading. That indicates a soil health problem. 

I think it is not like rabbits. Purslane contributes to soil health. Rabbits don't.

Is it a perennial in AZ? That would make sense to me as a problem.

Link to post
Share on other sites

Well, that would explain why the purslane I planted didn't do well in my garden. It was planted in good soil. 😂

I had no idea it was considered invasive. It has small, colorful, attractive flowers and was easily found in my local nursery. In fact, they've advertised several times in the last few years.

Wonder why it would be invasive in AZ and not south central Texas?

Link to post
Share on other sites
4 hours ago, Rosie_0801 said:

 

I'm all for free food myself. 😅

 

Eat the rabbits. 

4 hours ago, Rosie_0801 said:

 

Purslane likes high phosphorus, I was just reading. That indicates a soil health problem. 

I think it is not like rabbits. Purslane contributes to soil health. Rabbits don't.

Is it a perennial in AZ? That would make sense to me as a problem.

 

Rabbit droppings are really good for soil. 

3 hours ago, wilrunner said:

Well, that would explain why the purslane I planted didn't do well in my garden. It was planted in good soil. 😂

I had no idea it was considered invasive. It has small, colorful, attractive flowers and was easily found in my local nursery. In fact, they've advertised several times in the last few years.

Wonder why it would be invasive in AZ and not south central Texas?

 

Nurseries sell all sorts of invasive plants that they probably shouldn’t. It’s where people buy their bamboo and English ivy. 

I’m not anti-purslane. I started some from seed, but I treat it like a mint and keep it contained. It would be irresponsible to let it get away and ruin my neighbor’s landscaping. Often what makes a plant “invasive” is not that they’re just more successful than local species, but they kill them out to the extent that it effects local wildlife and food chains. 

I don’t know enough to know if purslane is bamboo bad, or just a landscaping nuisance like dandelions. I guess it’s different in different locations. I do know I’m sick of battling the English ivy and wish someone would have thought twice before letting it loose in my neighborhood. . 

Its hard to keep up with what is good and bad. I read an article the other day that said earthworms are invasive non-native species and I just can’t get my mind around that one. If it’s true, I’m happier not knowing. 

  • Like 2
Link to post
Share on other sites

I find purslane growing wild in my front yard -- southern exposure in a hot desert location, in a non-irrigated spot amongst gravel.  I have no idea where it came from.  Elephant Food, which is related to purslane, thrives in the most challenging spot in my yard -- southwest exposure, with reflected heat, in a pot.  I can readily believe purslane could become a pest in the right climate.  My Russian sage certainly did.  And Mexican evening primrose, which caused me to leave a community garden when it invaded from a neighbor's plot (she planted it on purpose!) and I couldn't get rid of it

 

  • Like 1
Link to post
Share on other sites
16 hours ago, KungFuPanda said:

Its hard to keep up with what is good and bad. I read an article the other day that said earthworms are invasive non-native species and I just can’t get my mind around that one. If it’s true, I’m happier not knowing. 

 

It is hard to find the right balance between preserving and improving soil health.

We have a heritage listed bugger-up over here. "Wow" someone said. "A freshwater estuary! Quick, heritage list that before someone buggers it up!" Except estuaries are not meant to be freshwater and now no one is allowed to heal that environment because it is legally obliged to stay buggered up.

 

So, back to Arizona, it is preferable to have bare soil than purslane? And I don't think anyone said, does it grow as a perennial up there?

Link to post
Share on other sites
21 hours ago, Rosie_0801 said:

 

Purslane likes high phosphorus, I was just reading. That indicates a soil health problem. 

I think it is not like rabbits. Purslane contributes to soil health. Rabbits don't.

Is it a perennial in AZ? That would make sense to me as a problem.

But it is desert - it is supposed to be "poor soil". The native species are adapted to that, and so really the goal isn't to turn the desert into better soil, but to keep out the invasives that outcompete/replace the native plants but don't provide food for the native animals. Replacing some of the few plants that do grow there with stuff that is toxic to the animals species would be bad news, I'd imagine. 

  • Like 5
Link to post
Share on other sites
16 hours ago, KungFuPanda said:

Its hard to keep up with what is good and bad. I read an article the other day that said earthworms are invasive non-native species and I just can’t get my mind around that one. If it’s true, I’m happier not knowing. 

Yes, it's true, there were no earthworms in the Americas until the Europeans brought them. That blew my mind when I learned that.  Also no disease ridden mosqitoes that carry malaria, yellow-fever, etc. Those diseases,  and the mosqitoes that spread them, were all importwd from Africa. The tropics here used to be much less lethal.

Link to post
Share on other sites

From a couple of sites, it's an annual. I also read said it's more of a common purslane (edible) vs horse purslane (not so edible/ toxic) issue.

Perhaps part of the issue is that vegetation springs up literally overnight when it's the monsoon/ rainy season? I could this taking off and then crowding out the more native vegetation that would be necessary for insects and animals of the area.

  • Like 2
Link to post
Share on other sites
55 minutes ago, Rosie_0801 said:

...So, back to Arizona, it is preferable to have bare soil than purslane? And I don't think anyone said, does it grow as a perennial up there?


It's not so much a matter of "preferable" to have bare soil -- that's a lot of what just naturally IS the landscape in the low/mid desert areas. I think if you cultivate purslane in a pot it might be a perennial. Growing wild, no, it's an annual "weed" in the low/mid desert area. Don't know if it grows much in the high desert or mountain elevations.

Arizona is a large state with *widely* varying climate zones, so there's no "one size fits all" as far as soil and invasive plant species. AZ elevations run from a low of 70 feet above sea level at the Colorado River, to over 12,500 feet at the top of the highest mountain range peak. AZ has everything from riparian (stream habitat), to arid low/mid desert with unique cacti, cattle grazing grasslands, to mid/high desert with scrub oak and juniper, to rocky canyon lands, to forested mountain ranges. The USDA plant hardiness zone map for gardeners divides AZ into 12 climate zones -- from 5a (high elevation) to 10b (low elevation/few if any below freezing temps).

In general, the invasive species tend to be more problematic in the low/mid desert areas and grassland areas. Those climates tend to have a lot of sandy soil, rocky soil, and clay-heavy soil, so a lot of bare ground naturally, or they have fragile ecosystems that are easily unbalanced by invasive species. Purslane and other invasive weeds don't tend to grow in the sandy or rocky soil, but do tend to take over in areas with more fertile soil, and crowd out the native slow-growing cacti, or the native grasses and ground covers. I've not really heard that purslane is the problem species in the low and mid desert areas of Arizona -- salt bush, salt cedar, and especially buffalo grass and fountain grass are the invasive species that get a lot of press and a lot of volunteer hours of removing it and replacing with native grasses.

The other reason invasive species are problematic in AZ is that many are annuals -- shoot up and put out a lot of allergenic pollen in the spring, dry out and die in the extreme heat and dry temps of May/June, and then act as a big fuel load for our summer wild fires, making some of the fires worst than they would have been.

Around my yard (mid-desert), the most invasive weed plants I deal with are wild mustard, milk thistle, and about 6 different plants that I don't know what they are, but they all either have very prickly leaves or have sticker-y burrs and goat-head stickers on them. Nasty things on your hands, but especially nasty for poor puppies who get them in their paw pads.

  • Like 4
  • Thanks 1
Link to post
Share on other sites
On 1/28/2020 at 7:23 PM, Rosie_0801 said:

 

Purslane likes high phosphorus, I was just reading. That indicates a soil health problem. 
 

"Healthy" soil is relative to location. Much of Florida soil, especially in the coastal areas, is just sand. It's doubtful our soil would pass the healthy soil test but is healthy for the native plants. By amending it we change it from soil for native plants to soil that will grow what we want it to grow. I imagine the same is true for Arizona, and even more so because of the desert. As a pp stated, the soil is perfect for desert plants. And purslane will crowd out those natives because it grows faster. Does that mean the desert soil is unhealthy? What does that mean? It's perfectly healthy for the native desert plants. And purslane is an invasive destroyer of those natives.

ETA: This is a subject near and dear to my heart. My state has more invasive plants and animals than any other in the contiguous United States and it breaks my heart to see native plants and animals crowded out.

Edited by Lady Florida.
  • Like 7
Link to post
Share on other sites
5 hours ago, Lady Florida. said:

ETA: This is a subject near and dear to my heart. My state has more invasive plants and animals than any other in the contiguous United States and it breaks my heart to see native plants and animals crowded out.

 

How did that happen? You have tourists from everywhere. Did they bring them in on their car tyres or something? Or was it like us and the cane toads, with some bright spark importing them for a terribly good reason?

 

(Mostly I've been thinking about agriculture, and how much damage conventional farming does. I know a desert is meant to be deserty, but in so many places (my area included) we're creating deserts where they needn't be.) I have red dirt residue on the tomato plant outside the door, and I should have to drive all day to find red dirt.

Link to post
Share on other sites
6 hours ago, Lady Florida. said:

"Healthy" soil is relative to location. Much of Florida soil, especially in the coastal areas, is just sand. It's doubtful our soil would pass the healthy soil test but is healthy for the native plants. By amending it we change it from soil for native plants to soil that will grow what we want it to grow. I imagine the same is true for Arizona, and even more so because of the desert. As a pp stated, the soil is perfect for desert plants. And purslane will crowd out those natives because it grows faster. Does that mean the desert soil is unhealthy? What does that mean? It's perfectly healthy for the native desert plants. And purslane is an invasive destroyer of those natives.

ETA: This is a subject near and dear to my heart. My state has more invasive plants and animals than any other in the contiguous United States and it breaks my heart to see native plants and animals crowded out.

Yup. Although I still can't bring myself to actually kill the cuban frogs when I see. them. But man - so many! And ones that were native to south florida moving north, etc. I was doubly angry about Florida Pusley when I found out it didn't even use to BE in this area! But that's not truly an invasive really i don't think. Fire ants - THOSE are invasive. And the invasive lizards, snakes,  etc. 

  • Like 1
Link to post
Share on other sites
5 hours ago, Rosie_0801 said:

 

How did that happen? You have tourists from everywhere. Did they bring them in on their car tyres or something? Or was it like us and the cane toads, with some bright spark importing them for a terribly good reason?

 

 

It happens so many different ways. Many plants were brought here years ago before people really understood how bad invasive plants can be. Some seeds hitch a ride on other plants. Animals get here so many ways. The Spanish brought hogs centuries ago and now we have a feral hog problem. People buy exotic pets then realize they're a lot of work so they let them out into the wild. Eggs arrive in plants. We not only have many tourists, we also have major ports into the U.S. and they arrive on all kinds of ships. It's pretty much out of control at this point.

  • Like 3
Link to post
Share on other sites

The biggest problem the US faces in biosecurity is the reluctance to restrict trade. So, you go into any pet store and you will see far more species from Africa, South America, Australia, and Asia than US native species. And if you see a US native, it's probably from a different region, like a California King snake in TN, or a corn snake in CA.  Herps, fish, invertebrates, birds, rodents, marsupials-almost all non-natives and potentially invasive. USFWS tries, but it pretty much takes an invasive already being established or a disease being epidemic before US law makers will agree to restrict something that is sold in the pet trade. States and localities sometimes are able to move faster, but again, usually it's after the fact.  Even if no one is ever irresponsible enough to release a pet intentionally, all it takes is one disaster (storm, fire, etc) to release non-natives. 

 

The same is true in garden centers. Almost everything there is non-native and potentially invasive SOMEWHERE in the US.  USDA tries, but  it is, again, an uphill battle to restrict anything. 

 

One of the things I loved most about Taronga Zoo was displays encouraging keeping NATIVE, common species as pets (and a focus on teaching kids husbandry of pets in general).  The Sydney botanical garden similarly pointed out native plants that are good for landscaping, etc. 

  • Like 4
  • Thanks 1
Link to post
Share on other sites
1 hour ago, dmmetler said:

The biggest problem the US faces in biosecurity is the reluctance to restrict trade. So, you go into any pet store and you will see far more species from Africa, South America, Australia, and Asia than US native species. And if you see a US native, it's probably from a different region, like a California King snake in TN, or a corn snake in CA.  Herps, fish, invertebrates, birds, rodents, marsupials-almost all non-natives and potentially invasive. USFWS tries, but it pretty much takes an invasive already being established or a disease being epidemic before US law makers will agree to restrict something that is sold in the pet trade. States and localities sometimes are able to move faster, but again, usually it's after the fact.  Even if no one is ever irresponsible enough to release a pet intentionally, all it takes is one disaster (storm, fire, etc) to release non-natives. 

 

The same is true in garden centers. Almost everything there is non-native and potentially invasive SOMEWHERE in the US.  USDA tries, but  it is, again, an uphill battle to restrict anything. 

 

 

Also, once such a species arrives, its natural enemies don't come with it. You end up with animals that have no natural predators to keep the population in check. With plants it can a double edged sword. On one hand, animals or birds sometimes like the newcomer better than the native plants and so end up spreading the seeds of the invasive plant. On the other hand, an invasive plant can spread so quickly that it crowds out native plants, which then decreases the population of the animal that depends on the plant. People are usually aware that animal species can be invasive but tend to think of plants as innocuous. They are just as big a problem as invasive animal species.

  • Like 3
Link to post
Share on other sites
On 1/28/2020 at 3:38 PM, Rosie_0801 said:

That's what is said about most non-native, non-commercial crops, isn't it? *shrug*

What native species is it crowding out?

Purslane is an indicator of poor soil health, as many weeds are. Is the problem the plant or the unhealthy soil?

that is the natural soil state in the area.  it's not "unhealthy".  AZ is mostly desert.

  • Like 2
Link to post
Share on other sites

AZ also has a wild horse problem for the same reason. It's an instructive parallel.  They came in centuries ago, have few natural predators, are devastating the ecological balance of the areas they roam, and yet people are unwilling to allow them to be killed because they like horses. It's a very rare person who can afford to keep them and Americans have a weird prejudice against eating horse meat, so the problem goes on.  And no, using tranquilizer guns to shoot mares with hormonal birth control isn't effective because there's no way to keep track of them or provide the man power to do it on a large enough scale to make it effective.  So on and on it goes with each horse consuming large amounts of forage and water daily in a place not able to sustain it and the native plants and animals suffer ....but most of those native animals they're not majestic and part of the romanticized American West Lore so nothing constructive is done. 

Don't get me wrong, I like horses. I grew up with horses.  My mother boarded horses. I've kayaked in the Lower Salt River with the wild horses.  At the same time I understand that long term consequences to both the native habitat and the wild horses if it's allowed to continue.

  • Like 3
Link to post
Share on other sites
2 hours ago, Lady Florida. said:

Also, once such a species arrives, its natural enemies don't come with it. You end up with animals that have no natural predators to keep the population in check. With plants it can a double edged sword. On one hand, animals or birds sometimes like the newcomer better than the native plants and so end up spreading the seeds of the invasive plant. On the other hand, an invasive plant can spread so quickly that it crowds out native plants, which then decreases the population of the animal that depends on the plant. People are usually aware that animal species can be invasive but tend to think of plants as innocuous. They are just as big a problem as invasive animal species.

yes.  here, we have both English Ivy, and Himalayan blackberries.   the ivy not only chokes out native groundcovers/shrubs - it will strangle and kill trees.  the blackberries can send out 20' canes as big around as your thumb in one season. (as well as choking out native plants)   the birds are so thoughtful to plant their seeds everywhere . . . . .  and the berries are tastier (and much larger) than our native blackberries.

 

triva - the "old west" is known for tumbleweeds. . . . . . it's an invasive non-native species introduced by Russian settlers who brought contaminated seed with them in the 1800s.  and boy has it spread.. . . .

 

eta: the blackberries - their thorns are VICIOUS.  

Edited by gardenmom5
  • Like 1
Link to post
Share on other sites
10 minutes ago, gardenmom5 said:

... AZ is mostly desert.


I know that's what people think -- everyone is picturing the Sonoran desert and saguaros down in the southern part of the state -- but only a little under half of AZ is desert. More than half of AZ is mountains and plateau ranges, which is the central and northern parts of the state. 😉 

  • Like 2
Link to post
Share on other sites
Just now, Lori D. said:


I know that's what people think -- everyone is picturing the Sonoran desert and saguaros down in the southern part of the state -- but only a little under half of AZ is desert. More than half of AZ is mountains and plateau ranges, which is the central and northern parts of the state. 😉 

desert is defined by the amount of rain in a given period.   not the terrain.

we actually have desert on the south end of san juan island. 

 

 

  • Like 2
Link to post
Share on other sites
11 minutes ago, gardenmom5 said:

Triva - the "old west" is known for tumbleweeds. . . . . . it's an invasive non-native species introduced by Russian settlers who brought contaminated seed with them in the 1800s.  and boy has it spread.. . . .

I grew up on Tumbleweed Ln.  My mom still lives there.  Yes, before it was surrounded by suburbs 10 years ago, back when it was farmland,  there really were tumbleweeds blowing around in the wind.

And it's noteworthy that all the agro and the unlimited building in the area contributes to the water shortage problem and affects native plant species,  which will also have a long term effect.  Some people call Phoenix (in the low desert) America's least sustainable city because of water issues.  

  • Like 2
Link to post
Share on other sites
7 minutes ago, gardenmom5 said:

desert is defined by the amount of rain in a given period.   not the terrain.


True, but above you made your desert comment in context with your soil/terrain comment, so I took that to mean you were conflating those ideas. 😉

29 minutes ago, gardenmom5 said:

that is the natural soil state in the area.  it's not "unhealthy".  AZ is mostly desert.

Link to post
Share on other sites
17 minutes ago, Homeschool Mom in AZ said:

I grew up on Tumbleweed Ln.  My mom still lives there.  Yes, before it was surrounded by suburbs 10 years ago, back when it was farmland,  there really were tumbleweeds blowing around in the wind.

And it's noteworthy that all the agro and the unlimited building in the area contributes to the water shortage problem and affects native plant species,  which will also have a long term effect.  Some people call Phoenix (in the low desert) America's least sustainable city because of water issues.  

I just thought it was interesting tumbleweed is not a native species. (it thrives in arid steppe terrain) Russian thistle, reportedly arrived in 1873..    it was in a report from eastern Washington where they recently had a 30' high drift of tumbleweeds closing the freeway and burying cars.  (Eastern WA is fairly dry, hot summers, cold winters. some of it is good farmland  - only if it's irrigated.)

 

Link to post
Share on other sites
29 minutes ago, Homeschool Mom in AZ said:

I grew up on Tumbleweed Ln.  My mom still lives there.  Yes, before it was surrounded by suburbs 10 years ago, back when it was farmland,  there really were tumbleweeds blowing around in the wind.

And it's noteworthy that all the agro and the unlimited building in the area contributes to the water shortage problem and affects native plant species,  which will also have a long term effect.  Some people call Phoenix (in the low desert) America's least sustainable city because of water issues.  

There are still plenty of tumbleweeds!  I have a photo on my phone of them blowing past my car while I waited in a school pickup line.  I've had to drive around them plenty of times on the road, and pull seedlings from my front yard.  And I live in the suburbs, not very rural at all. 

Link to post
Share on other sites
6 hours ago, gardenmom5 said:

I just thought it was interesting tumbleweed is not a native species. (it thrives in arid steppe terrain) Russian thistle, reportedly arrived in 1873..    it was in a report from eastern Washington where they recently had a 30' high drift of tumbleweeds closing the freeway and burying cars.  (Eastern WA is fairly dry, hot summers, cold winters. some of it is good farmland  - only if it's irrigated.)

I saw those pics.  It reminded me of a road trip my husband and I took to CA from AZ.  When we stopped for dinner all the cars at the restaurant had tumbleweeds on the front of them and under underneath.

Link to post
Share on other sites
10 hours ago, Lady Florida. said:

Also, once such a species arrives, its natural enemies don't come with it. You end up with animals that have no natural predators to keep the population in check. With plants it can a double edged sword. On one hand, animals or birds sometimes like the newcomer better than the native plants and so end up spreading the seeds of the invasive plant. On the other hand, an invasive plant can spread so quickly that it crowds out native plants, which then decreases the population of the animal that depends on the plant. People are usually aware that animal species can be invasive but tend to think of plants as innocuous. They are just as big a problem as invasive animal species.

I like that UF has approach this partly by creating non invasive versions of the popular, but invasive, species. 

So Mexican Petunia, which people love because of the pretty purple flowers and easy upkeep, is very invasive. So UF, rather than convince people to stop buying it, created a sterile version - no more worry of seeds spreading far and wide. ( you do still need to watch it spreading by runners, but that's controllable, it isn't crazy like bamboo or anything). 

Mind you, i STILL see people being blasted on the local gardening group for buying Mexican Petunia, despite the fact that the big box stores now exclusively carry the sterile variety. The gardening purists can't seem to drop the idea that it is evil. 

  • Like 1
Link to post
Share on other sites
6 hours ago, Kebo said:

There are still plenty of tumbleweeds!  I have a photo on my phone of them blowing past my car while I waited in a school pickup line.  I've had to drive around them plenty of times on the road, and pull seedlings from my front yard.  And I live in the suburbs, not very rural at all. 

My mom's house is now completely surrounded with suburbs for miles and miles until you get to tribal land to the east and southeast and the rest of PHX to the west and northwest. I think there's only a square mile or two left in her city that isn't completely built out, so that area doesn't see them anymore.  And there aren't many haboobs where you can only see a few inches in front of your face anymore.  They used to blow in over desert which was much closer when we were kids. The tribe has been farming the borderland, so the desert is much farther away now. We played in them because we'd all already had Valley Fever from the dust storms.  (I remember having Valley Fever.  It's rough and lasted for weeks. I read the Wizard of Oz series.) My brother built a sail on his bike for when they hit.  The tumbleweeds blew in more then too.   We knew it was coming because the sky changed to a different color of blue, the birds started "surfing" the wind, the air felt very different, and we watched "the wall" come in brown and high, then BAM! we shut our eyes, turned our backs to it and got sprayed with dirt and wind. Good times, as long as you didn't hit with a tumbleweed.

  • Like 1
Link to post
Share on other sites
8 hours ago, Lori D. said:


I know that's what people think -- everyone is picturing the Sonoran desert and saguaros down in the southern part of the state -- but only a little under half of AZ is desert. More than half of AZ is mountains and plateau ranges, which is the central and northern parts of the state. 😉 

Yep. You can pretty much find somewhere in AZ that will fit/seem like the same climate as somewhere in all the other 49 states. Arizona Highways magazine did a layout on this years ago. We're a pretty diverse state in many, many ways. We also have many "non-native" plant species that have been so taken with the various soils here, that they've thrived and aren't going anywhere. Even so, many of those non-native species are actually medicinal herbs. so there is a positive to that. Even purslane can have some sedative properties from it, just from eating it.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...