We have noxious weeds in AZ like the puncture vine or goathead: http://plants.usda.gov/java/noxious?rptType=State&statefips=04, but most "weeds" have a pretty flower like filaree or cranesbill. However, my HOA wants us to eliminate all "weeds" and plant growth which I do not agree with, especially since for many that means spraying large amounts of glyphosate. I am experimenting with orange oil, vinegar, and a miniscule amount of detergent in my sprayer. So far it is taking gallons, and the insects in hte soil don't care much for it, but my beautiful green yard is beginning to turn an ugly brown! I am doing this under protest as I love my filaree, london rocket, locoweed, bunchgrasses, starpoint/silverpuffs and daisy fleabane. Every day it is different in my yard this time of year, but now it will have to be eliminated. However, I love the common land trails by Oak Creek and Spring Creek so I comply.
Columbine in my garden
Starpoint or Lindley's Silverpuff in my yard
Swallowtail on My Lilac Bush!
Sculpture Done by a Beaver by Oak Creek
They are unfortunately taking down a lot of trees...