Guerilla Gardening (2015)

I'm telling you, go back and watch the video, or any other video on Tony Santoro's channel. The man is a legend who deserves more press. He absolutely embodies the hacker ethos, if in his own unique way. Autodidactic, anti-authoritarian, fiercely intelligent, sharply witty and indefatigably individualistic.

Like everyone else here, I sing high praise of Tony. His absolutely lovable one-in-a-million combative yet beautifully intelligent personality is perfect. I've developed a recent intense interest in revisiting my garden, which I attribute exclusively to stumbling upon his videos. Sometimes YouTube's Big Algorithm does something right. :)

Also, on another note - would you mind detailing which potentially invasive species you see in the photos, and in which regions it may be considered as such? I didn't see anything I noticed as to be particularly for my region.

In general, folks are going to buy plants @ Lowe’s/ Home Depot or their local nurseries. It’s not that easy to gain access to plants that are not compatible with your native biome.

I don’t think the chances are very high of someone buying seeds from a foreign seed company, germinating them at home, and planting a large scale public project like this.

Things like these are quite popular and people are for instance all 'for the bees!' while actually not knowing the basics of biology/biodiversity/habitat systems/... and they end up, unknowingly, doing more bad than good. Some of the before/after pictures raise my eyebrows because what was there first was something with a couple of native species and probably (hard to tell because I can't see pesticides being used, but doubt it) a vivid soil life. All providing food/shelter for the native chain of microscopic soil life to larger fauna. The picture after showed all grass/herbs gone and replaced with bare soil and a bunch of pretty-looking flowers. Now, you'd have to count to make sure, but the end result could very well be worse:

- digging is detrimental to soil life. It can straight out kill worms etc, destroys chains of fungi and so on. Yes it comes back, but it should be avoided unless really really needed.

- possible introduction of polluted/foreign particles when planting already grown plants

- many non-local (doesn't even have to be invasive) plants only provide food for generalist species (of which there's ample usually) and/or do not serve as host plants for many other species. I.e. you literally take away the home of fauna and replace it with a fast-food restaurant of which many don't like the taste.

- some of these (in some pictures, most I think) plants only live a year and need to set seed to start again the next year. Not a bad thing per se, but seeds don't thrive just everywhere. Ideally you have to select plants suitable for the specific soil conditions. Otherwise you have flowers one year, and the next year essentially nothing, and after a couple of years you're back to the start. Which could very well be better as I'm explaining, but essentially it's all wasted energy and a small setback which wouldn't have been needed. Altrnatively, people repeat the process because they want the same effect and the cycle starts again.

- possibly minor, but unless you're really lucky, already grown plants come in plastic containers and they have to be moved producing CO2 and so on

There's probably more things I'm forgetting but that's the gist of it. I understand the appeal of a wealth of colors and nice looking flowers but it is usually just not the best thing nature-wise. There are alternatives though, and apart from the really drastic things like 'change this forest to grassland'-style interventions, it's what the local nature conservation teams are doing:

- if you really want to throw seeds around, look around for what grows in the neighbourhood already and source them from there. After figuring out if it's a local species. These days the plant recognition from pictures is getting really good so you don't even have to learn all determmination aspects. Don't dig, just spread them out or stuff them in holes from mice etc.

- if there's patches which are getting wild and covered with only a couple of different species, mow them once or twice each year and get rid of the mowings. Look up when is the best time. Do get rid of the mowings, it's a key aspect to counter the abdundance of nitrous oxide. Takes some years, but grassland managed like that is sort of the summum of biodiversity (not considering other vegetation types that is)

- volunteer with your local nature conservation team, look, talk, learn, apply&spread knowledge

(last note: same goes for the rise in beekeeping which I see locally. Good intentions again, but often without enough thought. The honey bee species used most are generalists and meta-analysis of studies show that on average the effect on native single bees many of which are already endangered, is negative. Some studies showed no effect, none showed a good effect, and most showed a negative one. The local bees just cannot compete with the sudden introduction of a couple of thousand new mouths to feed.)

You can also ask if it has to be done in your city, per se. Would you be happy donating if it were done somewhere else and served other needs (e.g. reforestation)?

For example, planting things (or disturbing existing things) on private land or state or national parks is generally illegal and enforced (assuming you get caught, of course).

Planting anything on a controlled list (such that it is considered invasive or otherwise dangerous) is also generally prohibited and enforced.

If it's not one of those things, then it's generally going to be ignored as harmless. If something were to grow to a height such that it obstructs important views (i.e. of a pedestrian crosswalk), or poses a risk of falling on something (a poorly managed tree leaning over a road) then the city or state would likely tear it out. By that point, though, it's not too likely that you'll get the blame for planting it in the first place if you're acting as an individual.

All of this, of course, is just speculation based on assumptions about the potential hypothetical circumstances. IANAL and you would certainly want to think carefully about what you do to property that isn't your own.

I'm not from the U.S but the answer is of course yes, and they would vary wildly per council/municipality