Getting a regular supply of water to the root area is an important step in successfully growing a tree. My dad used to set the garden hose at the base of the tree and allow it to drip, drip, drip for a couple of weeks...not very practical in a parking strip situation.
I don't know your location but the water/air tubes are a good idea especially if there is not an irrigation system in place. I trust that someone will be responsible for adding water to the tubes on a regular basis?
Is there curbing in the parking lot? The curbing would prevent natural rainfall from being available to the tree roots so it will be necessary to have some type of watering system in place.
http://www.cityofpacificgrove....
In our area the city uses green bags (I think they are called Tree Gator) and the water truck comes around to fill each bag as needed. There is another brand called Garden Wizard.
http://www.goodideasinc.com/pr...
The plus for the water/air tubes is that no one can see them as they are in-ground. The bags are visible and (in my opinion) not very attractive, they add only water and not air, and they are an invitation for theft and vandalism.
