Cactus is a type of tree that I love because there is no time for people tree to water, which is one that I rarely have time and prefer raising Cactus because most Cactus needs water just once a week and can last for many years, and there are many many Cactus species, shape, which is a compact shape. Less space, beauty, and I would like to know what species are Cactus with water once a month and I really need?