It's a long way from South Phoenix where I was staying, but worth the trip. It is not inexpensive($24.95), but with a AAA card the admission is discounted 20%.
One wanders around the garden on mostly stone paths, but I saw many visitors in wheelchairs. The stones are crushed and so wheelchairs are pretty easily maneuverable.
There are many kinds of cacti and succulents. March is the ideal time to visit as many of the cacti bloom with wonderfully colorful flowers. One should plan a few hours to wander around the giant and small, ground-covering cactus plants.
In the spring there is a butterfly tent. This closes in early May as the heat is too intense, even under the cover of the tent. I cannot estimate the number of butterflies in the tent. They land wherever, even on the head of a visitor. One of the docents told me that the life of a butterfly is only several weeks, except the Monarch. The Monarch lives 6-8 months.
On an overcast spring day, it is a great way to spend some time appreciating Arizona nature.