avacados in the foothills

SO a guy calls today and wants to know ( after 5 hard freezes in the last 2 weeks) what avacado trees like. I said " the coast".
( he laughed hesistantly) ( no coast in El Dorado County)
Or a greenhouse.
But if you must try them here, in the ground, you WILL have to put a heat source and a blankie on it. The christmas lights that are good sized ( not twinkle lights) will put off enough heat to keep it at least 5 degrees warmer under the remay blanket you are also going to wrap them in.
 While this works great in this area for citrus at 1800' elevation, I am not convinced you will keep an avacado alive long enough to fruit. Time will tell...