Bloomberg News has.
…The designer’s intransigence put the Annenberg garden ahead of the emerging fashion for low-moisture, naturalistic landscaping on luxurious properties. Burnett embraced aloe, a spiky, flowering succulent that’s a favorite of hummingbirds, and he planted barrel cactus by the hundred….
Well that sounds expensive! But we’re here to help you out. We can plant barrel cactus for you by the singles. If you need hundreds we do have hundreds growing, but I suspect there aren’t a lot of you looking to replace your lawn with hundreds of barrel cactus for the drought. (but let us know if you are….)