Answer: Alice du Pont mandevilla is rated for cold hardiness zones 10-11. USDA zone 11 has average annual minimum temperatures above 40 degrees F. USDA zone 10 has average annual minimum temperatures of 30 to 40 degrees F. Las Vegas is in zone 8 with average annual minimum temperatures of 10 to 20F, which is quite a bit colder than the plant tolerates, so it would likely die back as an annual. And, the hot, dry climate is also problematic so the plant would likely be stressed. If you want to try one anyway, plant where it will receive morning sun, but afternoon shade, and is protected from winds. Mulch around its base to maintain soil moisture and cooler soil temperatures. You might want to consider a vine that is better suited to an arid climate (rather than a tropical climate), such as a trumpet vine or Baja passion vine (which attracts butterflies). Good luck!
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