[Arid_gardener] Re: Olive tree care

[RodMcQ6@aol.com]

Most trees grown in our desert soil will be happy with a fertilizer 
containing nitrogen only such as amonium sulfate, however if you happen to 
have an all purpose fertilizer, that will work fine also. 
        As for irrigation, deep watering once every week to ten days in  the 
summer  should be adequate unless you have an extended period where the high 
temps are over 110 degrees. Deep watering means the water must penetrate in 
excess of two feet deep.
        As your tree grows you should add more drippers and extend them so 
they are positioned at the drip line.
       The same irigation recommendations would also apply to your grapefruit 
tree. I suspect that the yellow leaves would indicate that the tree is being 
over watered. U. of A. Extension Fact Sheet MC 17 indicates that a four foot 
diameter grapefruit tree in mid summer would require 1.8 gallons of water per 
day. This amount increases as the tree grows. A six foot diameter tree would 
require 4.1 gallons per day. Be sure to not over fertilize, a one year old 
grapefruit should have only two to four tablespoons of fertilizer three times 
a year.
       Why not check out the Master Gardener Manual chapter on irrigation at: 
  http://ag.arizona.edu/pubs/garden/mg/arboriculture/watering.html

Good luck.
Rod McKusick
Master Gardener and Arborist