Question
Hello- I live in Chandler, Arizona. Yes, soil is bad (desert) and weather is hot most of the year. I have been spending a fortune on trees and shrubs ! Any general tips you can give me to help me maintain my trees and shrubs will be appreciated. I have citrus trees, shade trees, mexican palms, Lantanas, etc... The funny thing is I can plant two trees of the same kind only feet apart, and one will do fine while the other dies. This is not making sense to me, even though I take care of them the same way. I'm starting to think it has to do with how I plant them. Do you advise to add top soil or something when I plant a tree ? And what type of fertilizer do you recommend that is good for all plants ? Many thanks.

Answer
Hi Tony, Every plant has different needs.  Slight variations in planting depth, wind, sunlight, leaf count, reflected heat, mulch depth may cause one to dry sooner or stay too wet.  Don't assume the needs are the same, even for the same type plant.
If you are planting the right plant (one suitable for your area) and in the right place (correct amount of sun or shade), then we look towards improper planting if a plant dies before it's time.  The most common mistake people make is thinking their soil is bad and replacing it with what's called "top soil" or "garden soil".  You're plant must acclimate to your soil, so loosen and improve your soil, don't over-improve your soil.  For most trees and shrubs, you should use 60%-70% of your existing soil blended with organic matter.  Look at the rootball of your new plant.  If it's grown in a bark based mix, then use bark to blend with your soil so the transition zone is part of both soil types.  If the rootball looks like your soil, then just loosen your soil and use just a little organic matter.  Roots don't like change.
Plant high, your rootball should be slightly elevated above ground level.  Most roots are at, or near, the surface to compete for water and nutrients.  They need air as much as water.
When watering, there is no substitute for sticking your finger in the soil to test for moisture.  On every plant.  One may need water, one may not.  Even after they're established, you'll find one will wilt first in a time of drought.  Water deeply when you water to saturate the rootball and surrounding soil and water as infrequently as possible.
Check your pH and check your salt levels.  Your local garden center should be able to check both.  While you're there, have them recommend a fertilizer program for you.
Jim