First, my story. Early during my first marriage we traveled to Las Vegas several times a year from our home outside Chicago. One hot summer day, perusing around downtown, we discovered a small, lovely city park, in which were huge trees which appeared to be evergreens, but had no clearly discernible leaf or needle structure. Pic above is a good example. They withstand the searing Desert heat with no moisture beyond natural precipitation, yet grow to 60 feet in height. I learned the folks in the know out there called them "Smoketrees", because of their cloudlike appearance; they actually looked like greenish-blue clouds of smoke! I noted they were not watering them in any way. Originally from Africa and the Middle-East, the Tamarisk has many types. The biggest, above, Tamarisk Aphylla, is beautiful, to me, resistant to all-known plant pests, and can provide much-needed shade all summer from the unrelenting Desert heat, for both animals and humans. U.S. Department of Agriculture, however, exercising the usual governmental doctrine, believes the Tamarisk is sufficiently "invasive" that it should be eliminated from the U.S. The reasons stated are, of course, many. In defense of the Tamarisk, I offer this: During the Great Depression Works Progress Administration worked with USDA to "control excessive soil erosion" in the Missouri Ozarks, primarily within the 7-million acre Mark Twain National Forest. We lived within that forest for 13 years. As we hiked about, we were amazed by the everywhere-present rose bushes, which had crept into every possible non-plant area, amongst trees, shrubs, virtually everywhere, making it a chore to walk without encountering thorns tearing at the clothing, ripping open bleeding scratches on the arms. These bushes climbed trees, grew stand-alone sometimes 10 feet tall. Our neighbors universally despised government for not only the introduction of the rose bush soil erosion prevention, but for quite a number of unwanted interventions into these rural folks' lives. Those people, IMO, pretty much understood and knew full-well what they were talking about. A house near ours, here in AZ, has Tamarisk planted around the lot's perimeter, possibly covering several acres. The trees are magnificent, forming a towering wall impenetrable as a fence. They are perhaps 40 feet high and my guess would be at least 20 years old. AFAIK, authorities have not yet ordered destruction of privately-owned Tamarisk, but make no mistake, that move is very possible. I would fight them to the greatest extent possible. Above, Tamarisk have grown all along Green Wash south of Casa Grande, AZ, propagated possibly by pieces of branches which wash downstream during flash flooding. Tamarisk in bloom.