Ep 243 - Native vs. Invasive: Who Decides?

What does “native” really mean — and who decides?

In this episode of Garden Dilemmas, Mary Stone explores native vs. invasive plants, urban gardens, biodiversity, and ecosystem balance.

From dandelions to the marmorated stink bug, this episode reflects on what belonging means in a rapidly changing landscape. Inspired by Point State Park in Pittsburgh and the writings of Peter Del Tredici, Mary examines novel ecosystems, adaptation, and how urban environments balance native and non-native plants.

A thoughtful look at nature, resilience, and coexistence.

Link to the Companion Post: Native vs. Invasive Plants: Who Decides?  

May we tend wisely, welcome thoughtfully, and grow together.

 Related Stories & Helpful Links:

·         Ep. 99 - Wonders of Witch Hazel

·         Wonders of Witch Hazel - Blog Post

·         Point State Park, an Urban Garden- Pittsburgh, PA 

·         Ep 157. Benefits of Plantain & Dandelion 'Weeds'

·         Benefits of Plantain & Dandelion “Weeds” - Blog Post

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I'd love to hear your garden and nature stories, as well as your thoughts on topics for future podcast episodes. You can email me at AskMaryStone@gmail.com.   

You can follow Garden Dilemmas on Facebook and Instagram #MaryElaineStone.

You can also listen on Apple Podcasts, Spotify, and your favorite podcast app.

Thank you for sharing the Garden of Life,
 Mary Stone
Columnist & Garden Designer

More about the Podcast and Column:

 Welcome to Garden Dilemmas, Delights, and Discoveries.

 It's not only about gardens; it's about nature's inspirations, about grasping the glories of the world around us, gathering what we learned from Mother Nature, and carrying these lessons into our garden of life. So, let's jump in, in the spirit of learning from each other. We have lots to talk about.

Thanks for tuning in, Mary Stone 
Garden Dilemmas? AskMaryStone.com
Direct Link to Podcast Page

Transcript

Ep. 243- Native vs.Invasive Who Decides?

Sun, Mar 01, 2026 10:10AM • 13:57

SUMMARY KEYWORDS

native plants, invasive species, urban gardens, ecological balance, biodiversity, habitat stability, Point State Park, Peter Del Tredici, naturalized plants, globalization, climate change, dandelions, pollinators, ecosystem adaptation, human nature

SPEAKERS

Mary Stone

Mary Stone  00:00

Mary, Hello, fellow lovers of all things green. I'm Mary Stone, and welcome to Garden Dilemmas, Delights and Discoveries. It's not only about gardens. It's about nature's inspirations, about grasping the glories of the world around us, gathering what we learn from Mother Nature, and carrying these lessons into our garden of life. So let's jump in, in the spirit of learning from each other, we have lots to talk about. 

Mary Stone  00:25

Hello there. It's Mary Stone on the screen porch, and it's actually fairly warm today. I have to say. It got above freezing, and we skirted that huge storm here in Blairstown, New Jersey, that riddled the rest of the East Coast, where people had 20 inches or more, oh, my goodness, but certainly we are still in the winter mode. The garden rests, and I find myself enjoying the last of the quiet before spring springs and my hectic design season unfolds. I do kind of look forward to it, though. 

Mary Stone  00:59

I want to thank those of you who reached back after our last chat, inviting beneficial garden guests. It was such a delight to see Blaine Rothhauser's thoughtful LinkedIn post encouraging folks to tune in. Mary teaches all how to become better stewards of our surroundings. That is so kind, Blaine, because you do so much more in terms of your wisdom and knowledge of the natural world, and your photographs that we enjoy so much. Blaine shared something that made me smile- to bolster the reminder not to so easily dismiss insect pests as just that -pests. He included a remarkable portrait of a Marmorated brown stink bug. Yes, the bug that invades our homes each fall and leaves behind that less-than-lovely scent, he wrote. But head on, you must admit, it's cool. You may not want to kiss it on the palps, but you cannot deny its intricate form and color. 

Mary Stone  01:58

Palps on insects, for the novices such as myself, are the paired, segmented sensory appendages located on the mouthparts. I had to look it up. Blaine encouraged us to step outside of our comfort zone and consider its ecological attributes. When the stink bug first arrived from East Asia, its chemical defenses were unfamiliar to native predators, but over time, adaptation occurred. Birds, chickadees, starlings, grackles now eat them, especially fledglings, spiders, mantids, Assassin bugs take their nymphs, and even small mammals opportunistically consume over wintering aggregations. Does that erase the damage they do to crops and to impact our native insects, who are more productive? Probably not, but Blaine's deeper point resonates with me. Invasive species also teach us something. They reveal worldwide trade pathways. They remind us that often we are the cause, not the bug. Don't shoot the messenger, he says. And that leads beautifully into today's story that starts like this. 

Mary Stone  03:14

Hello, fellow lovers of all things green in last week's episode, Steve Rettke of Rutgers Cooperative Extension referenced research showing that urban gardens, after 10 or 15 years of cultivating plant diversity, nectar sources, and habitat stability, often become essentially pest-free when we allow stability to take root. Nature balances herself. His reference to urban gardens reminds me of a visit to Pittsburgh several years ago, a moment that continues to shape how I think about cities, plants and what it means to belong. A visit to Point State Park in downtown Pittsburgh highlighted the trip. 

Mary Stone  03:57

The mist from the glorious 150-foot fountain set at the point where the Allegheny and the Monongahela Rivers meet to form the Ohio River, providing soothing relief from the oppressive heat of the day. Pittsburgh was once known as the steel city, a thriving industrial powerhouse that declined into environmental and economic hardship in the mid 20th century. Today, it's considered one of the most livable cities in the world, reinvented and reimagined. 

Mary Stone  04:30

The city's picturesque 36-acre Point State Park is graced with many native species, strategically planned and planted, many of which I love to include in my own landscape designs. One that always captures my heart is our native, common or North American witch hazel that makes the staple astringent, Hamamelis virginiana, which is Hardy in zones three to eight, as we spoke about in the wonders of witch hazel in Episode 99 - I'll be sure to put a link in the show notes. I adore the smooth gray bark, supple green foliage and graceful vase shape. Witch Hazel blooms last far longer than many flowering trees, up to eight weeks or more, which is a fascinating feat of nature. Because fewer pollinators are active when it blooms, it must remain open longer for business. 

Mary Stone  05:26

Along the paths beneath the witch hazel at Point State Park are swathes of Christmas Fern, a favorite because of its evergreen clumping nature, and it has an added benefit of helping to control erosion. Then there's eastern red bud, which grows 40 feet tall, most adored for her early spring reddish pink flower clusters covering her branches before leaves emerge. 

Mary Stone  05:51

No question, native plants are increasingly celebrated and rightly so. But there's another point of view when it comes to cities. I had the privilege of hearing Peter Del Tredici speak about urban nature, human nature. He is widely respected for his research on urban vegetation and for challenging traditional notions of what belongs in our landscapes. One question from his talk has lingered with me, what is native to filled land such as New York City or Boston? His answer nothing. Therefore, he suggested restoring a pre-colonial native ecosystem in heavily filled urban land may not only be unrealistic, it may be misguided. In his field guide, Wild Urban Plants in the Northeast, published way back in 2010 he documented 222 plant species commonly found in urban areas. 33% are native to the north and Central America. 48% originate from Europe and Central Asia, 12% from Eastern Asia, 7% from Eurasia, and North America. So I can only imagine now, in 2026, what those ratios are. 

Mary Stone  07:12

The vegetation of cities is as cosmopolitan as its people, one of his slides read. He even showed statistics about Boston's population shifts over time that parallel the origins of the urban Flora, so fascinating, his tone was upbeat, encouraging - embrace the change he urged. Our world adapts. Still, many of us feel a pull to hold on to what we perceive as native plants, insects, and landscape. Is it an ecological concern or nostalgia, or something deeper in human nature, wanting things to remain as they once were? 

Mary Stone  08:00

Curiosity led me to read more about Peter's work, including his 2017, Boston Globe essay, amnesty for plants. He opens boldly, yank or spray all you want, the dandelion is here to stay in the article. He reminds us that dandelions, broad leaf, plantain, curly dock, and other so-called weeds arrived with early European settlers in the 1600s, seeds were embedded in hay, livestock feed and grain. The European invasion of North America was ecological as well as cultural. 

Mary Stone  08:38

He raises an essential question: How long must a plant reside somewhere before it earns belonging? European botanists classify long established non native plants introduced before 1500 as archaeophytes, essentially granting them quasi native status. Del Tredici proposes a similar concept for North America: any plant documented as growing spontaneously here prior to 1800 should be considered a naturalized American archaeophyte, with all the rights and privileges associated with being Native. He argues that globalization, urbanization, and climate change have permanently reshuffled the world's ecology. Novel ecosystems, cosmopolitan assemblages of species thriving in human-disturbed habitats, now occupy roughly a third of our Earth's land mass. He writes, "To deny their value," he suggests, "is to deny the reality of what humans have been doing to this continent for centuries." 

Mary Stone  09:46

That perspective gives me pause. Dandelions are near and dear to my heart. We chatted about them in Episode 157 their medicinal benefits, their role as early pollinators food, and their resilience. Recently, I've been enjoying tea brewed from roasted dandelion roots, earthy grounding a reminder that what we call weeds offers such beautiful gifts.

Mary Stone  10:14

 So where does that leave us? Perhaps somewhere between restoration and acceptance, between honoring native biodiversity and recognizing that the world, like us, is forever changing. Blaine's reflection on the stink bug. Stephen Retkke's photograph of a native spine soldier bug perched on an Echinacea. Peter del torici'ss, amnesty for dandelions and yes, the current often polarizing conversation about immigration in our own country, plants and people have always moved, sometimes by choice, sometimes by force, often by the natural way, seeds are spread by the wind, by critters, by humans sharing seeds, some cause harm, some cause environmental damage, which is real. Social tension from different points of view are real too. 

Mary Stone  11:15

So perhaps the deeper lesson is this: Belonging is not always about origin. Sometimes it's about contributions, about integration, about how adaptation occurs over time. Cities, like ecosystems, become multicultural, multifaceted, yet intertwined. The question may not be native or not, but how do we cultivate balance? How do we increase diversity and habitat stability so that resilience can emerge? Urban gardens teach us that after years of thoughtful planning, pests diminish, and diversity strengthens the web. We are one in this world with nature and with each other. The rivers converge in Pittsburgh, just as cultures converge in cities. Seeds travel, people travel, adaptation unfolds, and maybe our role as stewards of gardens and of life is to tend with curiosity rather than fear, to restore where we can, to accept what we must, and to remember that we too are part of this ecosystem, part of the whole. Garden Dilemmas? Ask Mary Stone.com.

Mary Stone  12:42

So thank you so much for listening to my story. I know that this is a heavy topic for many of us in so many ways. It is hard to see what's going on in the polarization of our world, but we can make a difference by sitting with each other in warm hearts and acceptance, and just realizing that this is a process that we are growing together. And the more of us that accept and open and realize the wisdom that comes from nature and gardens and wildlife and all that they do to cohabitate and adapt, we can just learn so much. And so I offer that as hope to all of us. Thanks again. See you next time on the screen porch. 

Mary Stone  13:26

You can follow Garden Dilemmas on Facebook or online at GardenDilemmas.com and on Instagram at hashtag Mary Elaine Stone. Garden dilemmas, delights and discoveries is produced by Alex Bartling. Thanks for coming by. I look forward to chatting again from my screen porch, and always remember to embrace the unexpected in this garden of life. Have a great day.