Walking tours of the gardens in collaboration with Desert Botanical Garden are still happening, however, are highly sought after tickets. Due to the heat, no walking tours are scheduled until the fall.
The Cactus Gardens may be seen as part of a guided tour, only. Tours are held September through June. Next set of tour tickets for January through May 2019 will be released on July 1, 2018. The castle and grounds have been open to guests on tours since 2012.
At one time they were conducting walking guided tours of the cactus gardens. That was I believed conducted by the Desert Botanical Gardens. You may want to contact them and see if those tours are still available.
The entire area is a cacti garden with an inner cacti garden to the left or west of the Castle or wedding cake. From the west part of the stone wall 3ft high you should see an old wood shack which was the tool shed for the grounds that is the area of the original cacti garden. Closed to the general public
You can't access the parking lot during closed hours.
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