Water is the problem. You don't see a lot of trees in southwestern cities because we don't have the water to keep them alive.
[1] - https://i.pinimg.com/originals/ec/c3/09/ecc309a7ebfb8f2235f1...
There are lots of ways to work with that problem and Brad Landcaster pioneered them in Tuscon, including curb cuts. You use eddie basins (and other design patterns), along with native perennials. In the case of Tuscon, those would be the native trees of Sonoran -- palo verde, mesquite, cholla, prickly pear, etc.
The curb cuts he pioneered inspired municipal laws, and Tuscon started implementing those and their own basins.
The mesa that Tuson sits on top of used to have an aquifer. That's been depleted and the city has been pumping water uphill. It does not have to be this way.
Hmmm. I wonder if he's related to Don Lancaster, who also lived in the Upper Sonoran Desert. Was mentioned on HN that he passed away last year.
I don't think people in Phoenix have lawns because there is more local water.
As far as Tuscon, Brad Landcaster's neighborhood has a tree canopy, and it's all watered by rainfall, and street storm water runoff harvested in eddie basins.
Tuscon is on top of a mesa, and its biome is the upper Sonoran. It's not quite high desert. The aquifer in the mesa has long been drained and Tuscon has to pump water from the central canal uphill to the mesa.
But it isn't as if the Phoenix is really flushed with water. An accident of legacy water rights from Colorado via the canal makes water available, but that doesn't mean that water supply is local nor sustainable.
Further, those existing water rights are being challenged by Native interest -- water rights are recognized by the age of the claim as senior water rights. Arguably, native tribes have the most senior rights, but even those claims that have been acknowledged by the legal system has not been historically enforced.
Tuscon is also where the Arizona laws allowing greywater was pioneered, as well as curb cuts. It seems to me there is more interest in this kind of stuff in Tuscon than there are in Phoenix.
Here are Tuscon development that are neither lawns nor xeriscaping:
Brad Landcaster's neighborhood - https://www.youtube.com/watch?v=KcAMXm9zITg
University of Arizona - https://www.youtube.com/watch?v=HtabtkWMxBc
Odd to be well so informed overall but somehow not aware of the SRP?! I think Phoenix is flush with water because of the CAP and SRP combo. It sits on the confluence of the Salt and Gila rivers while CAP water comes down canals from the CO plateau.
FYI, "turf" doesn't mean fake grass.
Not only have you added nothing of value to the topic at large, you provided incorrect information. The intent was obvious enough that you felt confident “correcting” me. Thanks for playing.
Also, most of those golf courses are taking advantage of 150+ year old water rights laws that no longer make sense in our current environment.
The worst is that much of this is state/nation backed (at least initially), so it's a bit of a drain as well.
If you do drip irrigation for such trees, at the minimum, the drip would need to be expanded as the canopy expands, and/or use deep watering spikes.
Better would be a deep mulch basin with intermittent deep watering.
In Phoenix (which is mentioned in the article), people have a tendency to use hybrid palo verde, trim the trees so they are more like the idealization of trees rather than the canopy pattern found in the wildland, and then have xeriscaping in a way that doesn't promote root growth. Some people will drip irrigate. The result are trees that blow down easily with the monsoon winds (which occasionally turn to hurricane strength gusts). It's not too hard to get chip drops during monsoon season because of poor stewardship.
In the nearby local park, there were a number of trees planted. That's good ... but the placement was not carefully chosen. Some of them will grow to shade the west setting sun along pathways, which is great. But there were other trees that were grown within the canopy of the overstory trees -- they are not going to grow great. They were also planted by digging large holes to fit them, but without any understanding of how rainfall will collect. Turf was added back (grasses compete with trees to fight over whether it turns into grassland or forest), rather than using mulch basins; the only reason they will do ok is because the park services flood irrigates the park. Lastly, the tree species chosen didn't look like they were carefully considered.
Mainly, the program looks like it has metrics on the number of trees planted, but there was nothing in the program or policies about tree species selection, planting methods, consideration of sunlight and rainfall patterns.
I don't think spreading poisonous trees across the American southwest is a good plan.
It's not really about planting a single species, but rather, introducing new ecosystems, so no one species is going to go wild and out of control.