Please help me before I make a mistake. I would like to do a mass planting of the lavender. I would like to know the best way to propate? As well as (most importantly) how will they do long term in a hot dry desert with extremes in temperature of 13 degrees in the winter and triple digits in the summer? Often days can be hovering over 100 and plunging to 60 at night. We get little rain, only 4" a year (though I do have sprinklers for supplemental watering). If the lavender is really hardy for my area then I will be using TONS of it for borders all over my acerage. Thank you!