Invasive Bradford (Callery) pear tree is banned in Pennsylvania | Hacker News Reader

Invasive Bradford (Callery) pear tree is banned in Pennsylvania

birdsoutsidemywindow.org

63 pointselliekelly56 comments

I grew up in midwestern suburbs where Bradfords were planted with great enthusiasm. I can see the appeal, they have neat symmetry, create no mess besides the leaves and don't get too big. Their semen-like flower scent filled the air in the spring, and they were drawn and quartered during the summer storms or winter ice.

I have fond memories of watching a massive summer storm from a friends bedroom and witnessing the moment his front yard Bradford split in half. The same tree would later split in half again during the winter. Invasive or not, Bradfords will always hold a special place in my heart.

To say Bradfords "create no mess" is about as true as "clean coal"! They create an enormous mess when they inevitably grow big and brittle and start dropping half of the tree on your lawn/house.

This does not factor into the decision making process of a property developer in the 90-00's. i stand by my original phrasing.

I had no idea that these were the plant responsible for so-called "Jizz Blossoms". There was always one week in the Fall where you'd smell 'em walking to class...

> Their semen-like flower scent filled the air in the spring,

They're all over GA Tech campus. We always compared the smell to cement though. :D

lol “semen-like” scent is right, we called them boiled-mushroom trees

THey taste better than they smell.

> Their semen-like flower scent

Well, not sure if that's better or worse than the scent of a hawthorn, that at best, can be described as "animalistic", but has always smelled to me like a decomposing possum, or dog poo.

https://www.irishtimes.com/news/sexy-smell-of-hawthorn-1.160...

When I see this article and the state announcement, I think of the Robert Pirsig Quote: "If a revolution destroys a systematic government, but the systematic patterns of thought that produced that government are left intact, then those patterns will repeat themselves in the succeeding government. There’s so much talk about the system. And so little understanding."

As someone originally from Pennsylvania - PA seems especially excited about invasive species. The spotted lantern fly was a big nuisance. Everyone talked about it. The spotted lantern fly and even this pear tree are not the enemy.

Invasive species thrive in ecosystems that we create. You don't want spotted lantern flys? You don't want thorny pear trees? Maybe ask who is defining the term "invasive species" and why they are defining them as such? Anyone thinking about cutting down your pear tree. Read "Beyond the War on Invasive Species: A Permaculture Approach to Ecosystem Restoration" [0]

0: https://www.goodreads.com/en/book/show/25782048-beyond-the-w...

Computer scientists even built a robot to scour Pennsylvania’s forests for the invasive tree-of-heaven, and poison them: https://www.semanticscholar.org/paper/Considerations-in-robo...

(The author was my theory of computation professor at University of Pittsburgh. Dr. Daley (RIP) commuted by Harley-Davidson and in his free time served as chairman of the regional forest stewardship council.)

> Invasive species thrive in ecosystems that we create.

In some cases yes, in other cases they simply out compete local species.

My country had managed to keep snakes out, but no doubt if they ever took hold here they would thrive in the wild, and harm the native bird population like the invasive stoats have. The invasive stoats live in the wild, far from people.

The book referenced actually provides numbers on this. Invasives out competing local species is a rarity according to the studies referenced in the book.

Here is another perspective too: https://www.vox.com/down-to-earth/22796160/invasive-species-...

> Invasive species thrive in ecosystems that we create. You don't want spotted lantern flys? You don't want thorny pear trees?

Non-native species get planted in environments we create (eg suburban yards). What makes them invasive is when they spread uncontrollably and displace native flora (dramatically reducing biodiversity in native ecosystems).

> Maybe ask who is defining the term "invasive species" and why they are defining them as such?

Sure, my definition above came from a hobby gardener friend who volunteers for a local environmental nonprofit.

> Anyone thinking about cutting down your pear tree. Read "Beyond the War on Invasive Species: A Permaculture Approach to Ecosystem Restoration" [0]

The reviews on that book are delightfully polarized.

> Invasive species thrive in ecosystems that we create

This is a common misconception

I've referenced articles and books in my other comments, and you're calling it myth. Care to cite something that supports what you claim?

You cite -one- book that maybe says what you want to think and looks more opinion than science. You write also a quote about politics and there is also that old feeling of "we humans are the worst" in the air that can feel justified but never solved anything.

I have a PhD in biology and frankly I'm sick of discussing this issue each time again and again.

Are you solely focused on plants here? Invasive species can also apply to animals. Invasive aquatic species have decimate local animals, and we didn't necessarily create those environments. There's also invasive plants in these aquatic systems as well.

Yes thank you for this clarification. Apologies for my being imprecise. Most of the reading I have done has been related to plants and the use of pesticides to intervene.

https://www.jstor.org/stable/1149643 https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111... https://naisma.org/naisma-resources/government-relations/the... https://www.semanticscholar.org/paper/The-potential-conserva...

Burmese pythons in Florida is another example of a pristine environment full of predators invaded (and modified) with no effort.

> Invasive species thrive in ecosystems that we create.

Is the idea here that invasive species cannot thrive in non-human-made environments? That is, environments we didn’t create?

Kind of, the idea is that no species would be invasive if we didn't create the ideal place for it to thrive. Invasives mostly thrive in disturbed areas and don't actually displace natives. The book I referenced goes into way more details, but in most cases invasives actually help repair damaged ecosystems. They are often pioneer species in the disturbed areas.

I've kinda had a similar perspective until buckthorn. Buckthorn is essentially eradicating native Big Woods forest, transforming forest that comprises an open understory with high canopies into dense tangles of buckthorn that choke out anything else. It also leads to these boom-bust nitrogen cycles that wreak havoc on the soil.

Many of these forests were just fine until buckthorn arrived. The problem isn't with buckthorn per se, it's in the destruction that it causes on native ecosystems. If the buckthorn was just here or there, an addition to the landscape, it might be fine, but it's not.

A solution to buckthorn overgrowth can't come soon enough because mechanical solutions, while effective, are very laborious.

Maybe there's something that could be imported to keep it in check (I recall reading buckthorn has some kind of highly specialized moth or something that eats it in its native range) but regardless of why, it's a problem.

> I've kinda had a similar perspective until buckthorn. Buckthorn is essentially eradicating native Big Woods forest, transforming forest that comprises an open understory with high canopies into dense tangles of buckthorn that choke out anything else. It also leads to these boom-bust nitrogen cycles that wreak havoc on the soil.

Buckthorn is the devil's plant. IIRC, it's a hedge plant, and literally turns a forest into an impassible hedge.

> Maybe there's something that could be imported to keep it in check (I recall reading buckthorn has some kind of highly specialized moth or something that eats it in its native range) but regardless of why, it's a problem.

IIRC, they're close to approving something like that for garlic mustard (which kind of does the same thing as buckthorn, except on the forest floor, and often gets bad after you deal with buckthorn). They've had to do a lot of testing to make sure it's very specialized and doesn't cause another invasive pest problem.

> A solution to buckthorn overgrowth can't come soon enough because mechanical solutions, while effective, are very laborious.

In Minnesota, they’ve been using goats. It’s still labor intensive, but the labor is performed by goats. Still, there are only so many goats, and there’s a lot of buckthorn.

I love the Big Woods ecosystem, and there’s very little of it left :/

This. My own "invasive is bad" epiphany was with honeysuckle in a SE Michigan park. They had grown so thick that nothing was able to grow in the soil under them - which had turned to dust, like the surface of the moon.

You're acting as if it's not possible to steelman the case against invasive species. This is a bit disingenuous.

Imagine we discover an alien planet with no predators. Should we allow ecological merging, with reasonable expectation of large biodiversity loss?

I'm not an absolutist; there are opposite examples - imagine that in the far future Australia were about to finish its tectonic journey to touch another continent and we expected new connection to result in massive ecological disruptions. Trying to prevent such a thing forever would be questionable.

The point is: you have to dig into reasons and outcomes, and can't resolve this kind of debate by simply saying "foreign bad" or "foreign good".

I 100% agree with you. You absolutely "can't resolve this kind of debate by simply saying "foreign bad" or "foreign good"

Imagine we discover an alien planet with no predators. Should we allow ecological merging, with reasonable expectation of large biodiversity loss. The problem is, the alien planet doesn't have a pesticides industry propped up around saying "foreign bad"

But I have no idea, and am not qualified to answer that hypothetical.

Not a glowing endorsement by someone in the field https://www.goodreads.com/review/show/2330107179?book_show_a...

"Someone in the field"?

I'm sorry but an anonymous comment on good reads, should not hold the same weight as a book that references academic papers.

In any case it isn't as black and white as "Invasive = Bad" one doesn't need to look far for that evidence.

https://www.semanticscholar.org/paper/The-potential-conserva...

https://spartina.org/project_documents/revegetation_program/...

I'm not really commenting on the thesis of the book, but pointing out what seemed like a valid criticism of the book overall. After skimming a few articles on the subject [1] it seem like the reviewer is not out of line with scientific consensus on the example he points out.

[1] https://scholar.google.com/scholar?hl=en&as_sdt=0%2C33&as_yl...

I am averse to the rhetoric about invasive species, but do believe that invasives are, in fact, frequently a real problem, not a contrived one. But I think that all the hatred poured on the plants/bugs/etc. is misplaced. IMO, the two most important things we can do are:

1. Create fewer disturbed environments. These plants are typically those that thrive in disturbed environments. As such, they may even be regarded as providing some kind of ecological service. Unfortunately, one of the reasons they out-compete natives is lack of predation. The Amur Honeysuckle I've been systematically removing still have beautiful leaves even in early Autumn, untouched by mold or bug.

2. Prevent the introduction of new species via the commercial nursery vector; hard to achieve any kind of ecological equilibrium when we are constantly disrupting it.

> Invasive species thrive in ecosystems that we create...Anyone thinking about cutting down your pear tree. Read "Beyond the War on Invasive Species: A Permaculture Approach to Ecosystem Restoration" [0]

The problem is they also thrive in (i.e. invade) ecosystems that we didn't create, and destroy or disrupt them.

If these species didn't invade wild ecosystems and stayed put in our backyards, then they wouldn't be invasive.

We also imported the first stink bug in the late 90s / early 2000s.

In the case of the spotted lantern fly, it's just the cost of global trade. It was not intentionally introduced like the Bradford pear.

> It took a while to realize that different sterile cultivars within the reach of the same pollinating insect could cross pollinate and produce fertile fruit.

“Life, uh, finds a way.”

I have one in my yard from previous owners, maybe this is the kick I need to cut it down. Maybe replace it with a native mulberry or pawpaw. Still have a few Trees of Heaven that were covered in spotted lantern flies the last two summers (2021 moreso). Those jerks destroyed my first grape harvest.

The bugs are not at fault here. The people who created the environment for them to thrive are.

Edit After Downvote: I get it - They were a major nuisance to you. Lanternflys weren't a one time thing. This has happened before - remember stink bugs? This has happened many times and it is going to get worse. Please don't shoot the messenger.

Stink bugs, gypsy moths, Japanese beetles... I get it. The wave of SLF hit Central PA right as my first grape vines were maturing.

But Tree of Heaven is also an invasive species, native to China like the SLF; it's their favorite host plant. The SLF invasion can be very "spotty". If I eliminate the stand of Tree of Heaven from my yard, the SLF will probably go elsewhere. I don't use pesticides or herbicides of any sort... just some copper fungicide for my fruit trees.

> The bugs are not at fault here. The people who created the environment for them to thrive are.

And when species like this thrive in the native environment?

Be careful with mulberries, I had one in my last place (not sure if it was native), and it dropped 10lbs+ of incredibly soft berries, so effectively black dye into my back yard daily for several months a year

Sounds great!

I have one across the street. Slightly less great when the birds eat the berries and your deck, house, sidewalk, and cars are covered in splotches of purple dye all the time.

There are many mulberry varieties spanning red, black, and white.

The white - look for Shahtoot - has long and slim fruit, with a much more delicate flavour. Can recommend.

Birds left ours alone for a decade, but once they discovered the fruit, they live in there from November through December (AU) relentlessly picking off the ripening ends of each fruit.

A bigger concern with mulberry trees may be their allergenic properties.

I'm fuzzy on mulberry distribution and don't feel like hunting the info down, but different species are native, introduced, or invasive in different regions. If you're going for native, you'd want to look into what belongs in your area.

Both, white and black mulberries are Asian trees, so be aware that you are replacing a Chinese pear by two Asian species of mulberry. The red mulberry is the one from US. The Texas mulberry is also from US but not so common in the market (probably).

White has a cultivar named Morus alba 'Fruitless' that is often used in cities. You can ask for it if you want a tree that will not stain the pavement.

The normal tree with fruits is a birds magneto but is a medium-big tree. Use it if you can provide the space necessary.

A post yesterday suggested "reusing" the Callery rootstock by grafting something native/tasty/otherwise better onto it. Might be a fun option if if it's not too big already.

https://www.thefruitexplorers.com/blog/2021/03/29/defenseofb...

Totally different trees. Callery pears are used because it is a 'fastigiate' tree. Is narrow and tall, but not much tall. Perfect for sidewalks. And is a tree for four seasons with splendid flowering and fall color.

Many fastigiate trees split in this way all the time because the branching happens in very acute angles and this creates a weak point.

Asimina and mulberry aren't good for sidewalks. Asimina is too short, parse and wide and spreads from the root. Mulberry is a tall tree, too big and too wide. Both made the soil slippery and a mess by fruits and leaves.

A possible replacement could be young american hornbeam that can be pruned narrow for a long time before it opens wide. there is not a lot of candidates for a narrow sidewalk. Landscapers deal with this problems and try to fix it all the time.

Either do the whole thing now, or do a branch at a time later. After a while, it’ll start coming down in pieces whether you want it to or not.

Another interesting Callery Pear fact (and basically the only one I know), is that the "Survivor Tree" at the 9/11 memorial in NYC is a Callery Pear: https://www.911memorial.org/visit/memorial/survivor-tree

I can't explain why, but it was the most moving part of our time there when we finally visited last year. And, the reason I haven't been able to bring myself to cut down the Callery that's growing on our property, despite my otherwise wholesale dedication to removing invasives.

Related from yersterday:

In Defense of Bradford Pear (2021) - https://news.ycombinator.com/item?id=29863917 - Jan 2022 (12 comments)

First thing we did when we bought our place was to start cutting them down. There were 5 of them, and they were at the point where limbs would start breaking off of them for no reason.

We were doing 1 a week, but that wasn't fast enough. One of them dropped a really large, live limb on a sunny, windless day. Easily could have killed someone.

It took another 5 years of aggressive use of roundup to kill the suckers that sprung from their roots all over the place.

Ha. My parents had a Bradford Pear which split in half due to an ice storm, and was replaced with a Cleveland Pear.

Can we change "Pa" in the title to "Pennsylvania"? As a non-american, it was difficult to confirm this (article only used the abbreviation, so I had to open a source about 3/4 of the way down and read that page's header image to confirm)

Sure. Changed now.

Thank you!

Reply on news.ycombinator.com