The other problem with non-native trees is their root structure. I'm sure you've all seen what the trees here in AZ do. Instead of their roots going deep, they spread wide and stay near the surface due to the dense clay. These roots do quite a number on infrastructure (sidewalks, streets, water lines) as they grow. Those little palo verdes don't do much for shade but their roots don't rip up the street.

I'm still all for more shade trees but they need to be planted properly.

Who said anything about non native? I didnt :D I am a member at the Desert Botanical Garden and think the plant life of the Sonoran Desert is amazingly beauitful, Id want to plant primarily native or other drought tolerant plants.

Im the one who always bitches about the lack of Saguaros downtown and the way Phoenix doesn't embrace its physical location and tries to look like Cincinnati too often. I hate the far flung suburbs but one thing areas like Desert Ridge do well is have nice densely planted xeriscaped medians and sidewalks.

I woudlnt worry too much about that. Go to neighborhoods like Encanto or Arcadia in the summer, they're not much more humid. In fact their much cooler and while probably a bit more humid its an OK trade off.

Also about this whole idea keep in mind its spaced out over 40 years. Its not like theyd plant 2 million trees tomorrow, so Id hope we could do it smartly and plan it properly. Find plants that dont use too much water, provide shade and don't tear up sidewalks, it can't be that hard. Finally, Im perfectly willing to trade 50,000 (or whatever the equivalent in water terms would be) new residents for a shadier, cooler, more beautiful city.

Who knows anything specific on the CHASE BANK building redux? Does anyone know what the new landscape/courtyard design will be?

I was referring to the people talking about dense shade dt. I'm not a botanical expert, I just don't think I've ever seen a native plant that would provide what I would call dense shade. As a member of the botanical garden, do you know of any native plants that would qualify as good shade trees? (it's hard to tell when typing so I'll clarify, I'm not being a smartass, I legitimately don't know). I would love to be proven wrong, I just don't know of any native shade trees.

Mesquite trees provide a lot of shade.. more so than palo verdes

Haha I just actually got a membership this week, so Im no expert....yet! But there are a lot of trees there that provide pretty good shade. The Sonoran trees that grow in the riparian areas like cottonwoods provide a lot of dense shade but obviously require more water however theyre resistant to monsoons. Theres also a lot of non native trees that are low water usage that work OK here like Chinese elm.

Like mentioned above, mesquites do a pretty darn good job (though theyre not the prettiest tree in the world) look at the big mesquite basque near the County Courthouse (fun fact the current location of downtown was chosen in part due to its adjacency to a mesquite basque).

Also if you look at the sidewalks along Scottsdale Road in front of SkySong theyve done an excellent job w/ just Palo Verdes. They more filter the light and not block it out but theyve planted so many and in a way that its very nice to walk in during the summer.

Planning it all out so youve got the trees in the right spots, man made shade structures, arcades, awnings, low UV materials, etc and you can make a big difference. Luckily the Urban Form Zoning has plans for all that stuff laid out, we just need to get it adopted sometime soon.

A mister does the same exact thing. It isn't going to turn Phx into Miami. This is a comment I would have expected on AZCentral. Its like saying, we need to stop building swimming pools because its becoming a swamp here. Phoenix actually used to have much more turf and shade trees in its past. Y'know, back when it used to cool off at night.

The trees would have zero effect on the humidity level here. Yes they do release water through their leaves at night, and yes it does cool off their surroundings. Arcadia cools off to say 75 degrees, while DT is baking at 88, which would you prefer?

http://i126.photobucket.com/albums/p...etallchase.jpg

I wanted to see what Chase would look like as a supertall. :D :shrug:

Eep. Freaking horrid.

Not dissing the photoshop job--it looks really accurate--but wow, I couldn't imagine something more out of place and weirder.

I firmly believe that the water used by planting even non-native species would be made up substantially if not an ultimate net positive by reductions in the heat island effect. Anybody who bitches about how much water grass uses hasn't walked downtown on a summer's night and felt the substantial cooling differences provided by even a tiny plot of green compared to rocks and asphalt. It's worth it.

That's uncalled for. Let me be more specific then. It's this post that I was referring to when I brought up non-native trees.

I agree with Hoover that mesquites provide fine shade, but since you used them as a specific example of what you don't want I assumed you meant non-native trees.

Yes a mister does the exact same thing, and no, I don't like them either. I hate walking down Mill when they have all the misters out, it just makes it muggy and disgusting feeling. And yes, I do think we need to build fewer swimming pools here.

Trees do not have zero effect. Increasing humidity is precisely how they cool off the air around them (evaporating water absorbs heat), it's not magic. No, it's not much, but compounded over millions of trees over the entire valley and it starts to build up. It's not going to turn Phoenix into Miami, but it sure as hell could turn Phoenix in june into Phoenix in August. Maybe it's just me, but Phoenix is absolutely miserable when the monsoon's here in august, I'll take 110 in June any day over 110 in August.

The heat island is caused by many factors, but humidity is actually a part of it. Part of the reason it cools off less now than it used to is exactly because of the swimming pools and country clubs that raise the humidity, which acts like an insulator and keeps the heat in at night. It's the same reason the temperature doesn't drop as much on a cloudy night. Sure it feels better right next to the grass or right under the tree, but it also affects the larger climate of the valley. Everything you do has a consequence. Maybe you think the consequence is worth it, but it's asinine to ignore the optential consequences.

That really wasn't my main point in the first place though. The main reasons to stick with native plants wherever possible are water usage and to a lesser extent, aesthetic (I like cactuses and mesquites and palo verdes... that's why I live in Phoenix).

Non-native trees use substantially more water than native trees like mesquite trees. You can plant and cool the area off using native species far more efficiently. Phoenix uses drastically more water than is replenished. We need to be finding ways to reduce our water usage, not ways to use more. It's like getting your paycheck and thinking of the coolest new stuff you can buy rather than paying attention to your growing credit card bills. I'm all for planting more... lots more... trees around the city, but they need to be low water, preferably native trees.

In addition to saving water, native flora also pays homage to the geography in which we live. The prolific use of non-native species detracts from our city's identity as a desert community. If people want more local culture and identity in this town, a great place to start is by bring Sonoran plants back into our urban environment.

Mature Palo Verde and Mesquite provide more than adequate shade, bloom beautifully in the spring (Palo Verde turn an amazing yellow which can be striking in large numbers), and are distinctly part of our local landscape.

http://farm4.static.flickr.com/3601/...f3ac76d2e3.jpg

This is a shot from my flickr last spring. Don't try and tell me that tree doesn't provide good shade.

Maybe here in the desert our definition of "good shade" has been blurred, but actually, they really don't.

As touched on earlier, they can help filter the sun's light, but not entirely shade us from it. With Palo Verdes you either need them grouped in tight proximity together or they need to have several years growth on them before legitimate shade can be provided. But again, even in those instances, it is rarely solid shade. Architecturally, Palo Verdes can be attractive trees, with their thin, snake-like, windy branches, but when it comes to genuine shade or effective shelter from the sun's heat, there are definitely better trees - including native types.

Many shade structures are permeable so some light can reach the ground - they still are quite cool beneath and are effective year-round when temps are lower:

From Google:
http://www.bamboohabitat.com.au/imag...o3_gazebos.jpg

http://woodsshop.com/kits4/images/Ja...tructure_c.jpg

http://www.theartoffice.com/pdcpc-sh...cture-img1.jpg

http://www.library.unlv.edu/arch/aia...03/b03054t.jpg

http://www.calown.com/images/shade_structures1.jpg

Compare the shade provided by these mature Palo Verde:

http://taylormadedesigns.typepad.com...e577970c-320wi

http://www.mesa-goodlife.com/images/PaloVerde.jpg

http://latimesblogs.latimes.com/phot.../cercidium.jpg

Plenty of other desert trees will do just fine, as well.

You know what else provides shade?

Lots and lots of tall buildings! http://www.evilbore.com/forum/Smileys/default/hyper.gif

I agree...that's how it's done in Manhattan. Granted, Phoenix will probably never be like Manhattan but there are places in Phoenix that you can strategically place taller buildings and provide great shade. Palo verdes and mesquite trees get pretty damn tall for the lack of rain that they get. Compare that to other places in desert climates worldwide and you'll be happy to see the amount of trees in the Sonoran desert.

Aren't Palo Verdes horrible at resisting high winds associated with the monsoon when they are trimmed into the tree shape that we prefer them in? I always see them uprooted in parking lots. The tree naturally is more bush like if you look at them in the desert.

Haven't seen palo verdes get knocked over much compare to mesquite trees. But here in Tucson I have seen the bigger trees that are like 300 years old and they are fairly tall and their roots are well established. My Palo Verde I just planted last year sits about 15 feet tall and is growing fairly well. My two mesquite trees that were planted when I bought my house in 2006 are about 20 plus ft tall. You are correct HX guy, they are more like a desert bush but they can still grow 20-40 ft high so that's gotta be better than nothing like in the Sahara desert or even the mojave desert.

I read that the Sonoran desert is the "wettest" desert in the world with "two" monsoon seasons.

I think we can all agree the city and downtown need more trees and thats the bottom line. Im more in the go for native plants due to the low water usage and unique look camp, but its whatever. If the city ever embarked on a plan to plant 50K a year I doubt they'd be 100% native. Maybe some experts could figure out a good formula like 40% native, 40% non native but low water use and 20% 'traditional' or something.

I do agree that the filtered light does a good enough job, keeps the sidewalks from getting too hot, etc. Keep in mind that a lot of the Palo Verdes planted downtown and around town arent at maturity since the trend to go to xeriscaping is so recent.

Uh did I miss something? Was there official news that building was going under renovations?

EDIT: Also on a completely unrelated note: I was driving by the (quite lovely) new University of Phoenix buildings on the 10 today and I got to thinking, does anyone else find it strange that UofP doesn't have any Downtown presence? Their focus seems to be on a lot of night classes, working adults, etc. so it seems like being adjacent to downtown would be a smart move for them. I know since the economy is down and they just spent a lot of money on those new buildings its not likely to happen anytime soon, but it would seem wise to me for the City to try to work to lure them to build a downtown campus. I know they offer both business and nursing programs & both of those could seemingly work well downtown.

Chase building is redoing their outdoor landscaping. They are taking out all of the dirt and plants from the courtyard and big planting walls. They have jackhammered out some stairs. I saw them bringing in pallets of cement bags. I have not found anyone who can tell me what the plan is. I sure wish they would totally remove those walls that surround the block. Remove them and make it a plaza that is more open to the public. It could be a great space.

Yes, it is the desert w/ the most rainfall, thankfully. it has 2 rainy seasons (one of which is monsoon.)

And I totally agree w/ you Hoover RE: UofP and have thought the same thing. i think the city should really pursue other higher education facilities such as it did w/ ASU, such as a Catholic univ. i think we are the largest city without one. how about resurrecting the really old plan to have a BYU Campus here?