Cacti are slow growers . Fertilizers should be used sparingly except for epiphytic cacti. Many cacti require a cold treatment during the winter to get them to flower. Areas under overhangs on the south side of buildings suit them well. In the autumn, plants lose water, become wrinkled, and collapse on the ground.
Plants become turgid again in the spring when the soil warms.
In late spring and summer, Prickly Pears produce large, showy yellow flowers. The Little Prickly Pear is rare in Wisconsin, but common in other parts of its range. However, other cacti are rare throughout their ranges. Many of these are endangered because they are of very limited distribution or because they are of interest to collectors for private or commercial interest and have been over- collected. These cacti are listed int he Federal Register put out by the U.S. Fish and Wildlife Service and are protected by Federal Law.