I'm in Colorado and have a lot of open space behind the property so the gardens get plenty of things growing in them that I don't want. My two biggest problems are deer and spurge. This message is strictly about ways to control both cypress and myrtle spurge, as they're both spreading like crazy, and they have extensive root systems that make it almost impossible to control by digging them up. The myrtle spurge also has a fairly hydrophobic surface, so sprays don't stick very well.
If anyone has had experience combating these things (which are class A noxious weeds in CO) please pass along any knowledge you've gained trying to eliminare, or at least keep these things in check.
Thanks!