I don't care if trees are desert or not. Paramount to downtown, when deciding between thick shade and water conservancy, is thick shade. It's a matter of function and transportation. If there are desert or even native trees that can achieve that, all the better. But too many people just look at the width of a tree's canopy instead of also considering the amount of sunlight that gets through. Most desert trees (in what I understand to be desert trees) let copious amounts of light through their thin canopies. Those trees don't belong in locations that need shade (e.g. streetscapes).

I disagree. This is true of Palo Verde varieties and Palo Brea's but otherwise it doesn't seem to be.* Even the Palo variety trees at full maturity provide good shade. Mesquites (especially Chilean) for instance are quite dense, as are Ironwoods, so are Arizona Ash and thats not to mention the more riparian zone trees that are native to the Sonoran Desert trees like Texas Mulberry, Arizona Walnut, Arizona Sycamore, and of course Fremont Cottonwood (though the latter is no good for streetscapes, too thirsty and can knock up sidewalks. Though its great for parks with flood irrigation).

I think desert plants get a bad name due to poor implementation. Go to the DBG and you'll find plenty of deserty shade.

*I think Palo's can work really well provided there's enough set-back by the buildings. For instance, the State wanted to plant Desert Museum Palo Verde's (a gorgeous tree, especially in Spring) along the Capitol Mall on Washington Street. However, because the "historic nature" of the Street only had Palms thats all the State/City could plant with the funds they got for the improvement project from the Federal Government. So because some dummies 100 years ago didn't plan for shade, we're screwed out of it now.

Desert Museum Palo Verde's would've worked GREAT there since all the buildings are set well enough back from the street that a row could be planted between the sidewalk and street and either a double or single row could be planted between the sidewalk and buildings allowing a true canopy and basque to grow. The Palo Verde being our State Tree & all it would've made sense too, but it was a no go w/ the Feds. Though there's hope in the future that funding from another source will allow Palo's to be planted.

I think its a State thing, I'm looking into it, that seems to be what I recall.

Ok I'll make a separate post for this so its clear.

It looks like the Arizona Department of Water Resources has a list of drought tolerant plants that it allows Cities to plant in their right of ways. This PDF shows all the plants for the PHX area, I assume they have separate documents for Northern Arizona, Tucson, etc:

http://www.azwater.gov/azdwr/WaterMa...WU_Plants1.pdf

There is a pretty good variety of native and non native drought tolerant trees on the list that provide quality shade. I don't necessarily think the list by the State is the issue,* I think often the City is just lazy with its design and implementation when planting in the Right of Ways.

All of these are on the list and provide more than their fair share of shade:

http://www.bonsaisolutions.com.au/images/acacia1.jpg
Wattle Acacia

http://ag.arizona.edu/pima/gardening..._populneus.jpg
Bottle Tree

http://mgonline.com/media/Images/b/bottlebrush02.jpg
Bottle Brush

http://latimesblogs.latimes.com/.a/6...6811989970b-pi
Beefwood (this one would be extra nice Downtown due to its height it would look nice next to taller buildings).

http://nmgrassmasters.com/pix-trees/celtis_ret2.PNG
Western Hackberry

http://www.gardensandplants.com/imag...%20siliqua.jpg
St Johns Bread Tree/Carob Tree

http://www.dirtdoctor.com/pics/content_img.976.img.jpg
Mexican redbud

http://www.bunatexas.net/images/siteinfo/redbud1.jpg
Texas redbud

http://tclawnservices.com/images/Flo...ilk%20Tree.jpg
Silk Floss tree

http://www.elginnursery.com/images/f...Sissoo_380.JPG
Sissoo tree

http://www.danheller.com/images/Cali...s-tree-big.jpg
Eucalyptus

http://www.performancenursery.garden...otos/2205a.jpg
Australian Willow

http://www.floridata.com/ref/g/image...r_skycole1.jpg
Honey Locust

http://img97.imageshack.us/img97/437...232646tbuz.jpg
Ironwood

http://www.delange.org/PineAleppo/Dsc00318.jpg
Aleppo pine

http://img845.imageshack.us/img845/1...einromearp.jpg
Umbrella pine/Italian Stone pine (these are bad ass looking, I'd love these Downtown somewhere)

http://www.tree-land.com/images/chin..._tree_f_lg.jpg
Pistachio tree

http://www.delange.org/AfricanSumac/Dsc00472.jpg
African Sumac

http://ag.arizona.edu/pima/gardening...inus_molle.jpg
California Pepper Tree

http://www.delange.org/BrazilPepper/Dsc00226.jpg
Brazilian Pepper Tree

http://whtrees.org/images/tree_of_the_month.jpg
Tipu tree

http://www.houma.com/Portals/0/images2/bar1.jpg
Chinese elm

So as we can see there are plenty of drought tolerant tree's we could plant in our downtown without having to turn to thirsty Ficus or whatever. Many of these are "desert" trees (though not all necessarily from our desert) and the ones that aren't work well in our climate.

*Though like I said, I do wish Jacaranda was on the list. Lining Central Ave with Jacaranda's would be amazing and beautiful.

Like i said "as i understand desert trees", which you just showed might be a shallow understanding. My understanding is primarily based on what I see CoP constantly planting.

Granted, some of those trees you posted aren't appropriate for pedestrian shade (e.g. Bottle Brush, Silk Floss Tree, etc), but some of those would be awesome (e.g. Umbrella Pine, Pistachio, Sissoo, Western Hackberry, etc).

I also want to point out that ficus trees aren't as water thirsty as people think. They are fig trees that need only moderate water in the summer, and other times of year they need just enough to not dry out. They need lots of sun, and frost damages them. It sounds like a pretty fitting tree for our climate if you ask me.

(*Disclaimer: I am not a horticulturalist by trade nor hobby.)

I'm certainly not a plant/tree expert either, I just know the people who are always paint Ficus in a negative light as being a bit overly water thirsty for our climate, so I just took their word for it.

I guess my larger point is: I think planting desert & semi-desert plants is good for PHX not just from a water use perspective but also from a uniqueness perspective. Everything in the U.S. from St Louis eastward (sans Florida) basically looks the same vegetation wise, Phoenix should be happy it has such a unique climate and embrace it.

Doesn't it seem silly that there aren't any Saguaro's Downtown for instance? I think I know of maybe 2, thats ridiculous. The City needs to get over the idea that they can't plant Cacti because they have spines on them. Its not like the citizens are whirling dervishes bumbling down the street & going to fall into one.

Basically I just want Central Phoenix to be super dense desert landscapping, that would be amazing, something like this house in Paradise Gardens from lasts years Modern PHX Home Tour:
http://modernphoenix.net/hometour/20...0_mike_174.jpg

That would be awesome.

aleppo pines are prone to disease here.

My personal favorites are Chinese Elms. Tehy have a great sound when its windy, and I find them comforting. I had one in my front yard as a child and thinking about it makes me nostalgic and happy.

I can just imagine cacti lining pedestrian and bikelanes, what a horrible idea. Saguaro do no do well in the soil in Central Phoenix; it takes some effort to get them growing. If you look at the photos you posted, the ironwood and palo verdes let in "a copious amount of sunlight" like downtowner said in an earlier post; not very effective in an area that should be densely populated. Desert landscaping is great, but in the city unfortunately, it contributes to the heat island effect.

Where did I say anything about bike lanes? We ought to have saguaro's in parks, plaza's, patios of restaurants that are landscaped, etc. Not having saguaros, the thing that people associate with Phoenix more than anything else in our Downtown is what's idiotic (to use your insulting phrasing).

Well I actually didn't post a picture of a Palo Verde or any Palo anythings. Ironwoods filter light more than completely blot it out, but thats fine, they're still solid shade trees.

To say that Desert tree's contribute to the heat island effect is flatly untrue. I challenge you to go to Home Depot, get a thermometer gun, then go take a reading of the Municipal Courthouse plaza. You'll find its quite a bit cooler than surrounding non shaded man made sidewalks and the like.

Do they blot out the sun as much as Ficus? No, but they don't need to if you use proper design and maintain them. Downtown Phoenix is where it is in part because of the presence of a Mesquite basque, it makes sense to plant trees like that Downtown.

Due to our climate the trees we plant and the way we shade our City is by its nature going to be more complex than in some other cities. It will take a combination of "right tree, right place" tactics, architectural shading, permeable paving, water features to foster micro climates, etc.

If you want the City to plant Ficus, Fremont Cottonwoods or whatever else that will totally block the sun you're just pissing into the wind. Its not going to happen, they use too much water for Arizona & the Cities liking. You may as well accept that new Ficus aren't coming to Downtown right of ways and spend your time trying to find ways to shade our streets without emptying the canals.

Saguaros NEVER grew in Phoenix' alluvial soil; if you understood why farming, citrus, etc started in this Valley you would understand why it isn't idiotic that cactus do not naturally occur on the valley floor. Simple as that. Still, urban planning calls for trees that provide intense shade. Desert plants don't cut it, also simple as that.

"You'll find its quite a bit cooler than surrounding non shaded man made sidewalks and the like." -HooverDam

Which is why we need big trees to shade them; ornamental grasses and cacti aren't going to cut the effects of these man-made things in an urban environment. And I never listed ficus as a tree for downtown, that was someone else. I highly favor pistache and fan ash, etc which do the job; no "screening" of the sunlight but 100% shade. Check out Civic Space Park to see the difference between the shading and cooling at Phx Muni and the Pistache and other leafy greens at the park; this would include Portland Place Park and Hance Park.

I assure you I understand completely the Valley's agricultural history and your highly insulting posts really need to stop. I've read nearly every book, watched every bit of media and done extensive hours of research in the Arizona Room on the history of Phoenix and Arizona. I don't need a history lesson from you or anyone else.

Saguaro's may not have been in heavy prevalence around the area thats currently Downtown but that doesn't mean they can't be grown there. The site where Downtown is was a large mesquite basque and those basques often crowd out other vegetation forms as the roots connect below ground and give the entire earth a spongy texture.

To try to say that Saguaro's can't be grown Downtown is silly as there are presently a few in the Downtown area (Cesar Chavez Plaza).

Please back up your arguments with facts or stop. You can not just say something is a simple fact like that when its not. There are times when native desert trees can be used in an urban setting to great effect for shade, to battle the urban heat island, etc. You're pissing into the wind if you deny this.

Again, "Right tree, right place" is what we need. Palo Verde's and Mesquites won't cut it for every application, I'm not arguing that. I'm saying that entirely excluding them is just as foolish as wholly relying on them like the City tends to do with its lazy design.

Where did I say they would? Your arguing against something I haven't said or implied in any form or fashion. Phoenix sits in the most beautiful desert in the world, we ought to embrace that and use cacti decoratively.

I was just using the Ficus as an example of a shady tree thats not on the approved list.

Thats fine, I'm OK with any tree on the approved list going in Right of Ways and have said multiple times that list should probably be expanded slightly to include trees like Jacarandas.

My only point is we should try to use native and desert plants as much as possible as they give the City a unique look.

If your entire argument is that the City of Phoenix does a poor job designing streetscapes, shows a lack of creativity, etc. you won't find any argument from anyone. Remember I was the one who pointed out what an embarrassment the job they did on 2nd Ave South of Fillmore is.

Let me get this straight---no saguaros because they are not indigenous to downtown. However, we should plant a bunch of trees that are not indigenous?

Based on the photos from above, it looks like there are ample desert trees that could be planted to provide great shade. If you can get good shade without using excessive water, then why not do that? If state or city law limits you on trees, why not work with what you have? The one definite is that the City is retarded for planting shitty trees that do not provide shade. Looking at old pictures of downtown, there was ample shade provided by desert-approved trees. I'd be fine with returning to that.

I am not a botanist or horticulturalist or even a gardening enthusiast, but why couldn't you have shade trees AND saguaros? Shade would be awesome to have, and at the same time, it might be nice to have saguaros around town to give us a unique flavor.

I'm not against Saguaros per se, but too many would just be ridiculous. And around the convention center, desert vegetation like hooverdam supports does little to add comfort. It is much too hot and little shade is provided especially on Washington. Compare it to Portland St and the differences are obvious. to make the city unique, we should rely on architecture and ambiance IMO. Furthermore, there really weren't any native trees on the valley floor either except for riparian areas, washes, along the river banks, etc but in a built environment like a city, improvisation is important for success.

Therefore, using the most appropriate mix of vegetation is imperative and many desert plants aren't appropriate for the needs of a city. While there were many trees on the list that would work for downtown, calling them desert trees is wrong. The argument here is using more of the variety listed that will provide appropriate heat abating shade, palo verde, mesquite and even ironwood fail to meet that criteria.

This was a discussion on another blog, Rogue Columnist, but it is interesting and important for future development along the light rail corridor:

http://www.azcentral.com/community/p...-stations.html

Recently went to Desert Botanical Gardens and they had a display on this one occurence that a saguaro was shading itself under a palo verde. Said its common to find out in the open.

As children, cacti can't take full sun so they start out in the shade.

I just planted a Chinese Pistache in my front yard about 5-6 months back. My neighbor planted one as well, albiet smaller, and a mesquite. I shudder to think how long until mine resembles that being only a 36" box.

Do you have flood irrigation. 5 years and it will be close if so.

Every 2 weeks (I do put some hose-water on it to bridge the gap between irrigations though).

My lime tree in the back yard is really struggling this year though. Full sun all day, and requires daily watering to keep it going.

deep water is best. Soak it deep!

Unless it's in a pot, you don't want to water it every day. Water it for a longer period of time once or twice a week in the summer, less than that in the winter.