For us, this fast-growing but compact opuntia makes a 3' tall x 6' wide deer-resistant mound (in 5 years) of 6" grey-green spineless pads. In August, the clump is topped with large, bright yellow flowers...a hummingbird oasis, followed by large red "pears." Well-drained winter soils are vital for best performance.
As to be expected, the prickly pear cactus is extremely drought tolerant, so when it doubt, water it less than you think it needs. In most areas, your typical rainfall will likely be enough for the cactus to thrive but if not, you can plan to water the plant every two to four weeks.
As with most cacti, the eastern prickly pear does best in full sun for at least eight hours a day. That being said, it can handle partial shade if it's planted in hotter climates, like a more traditional desert landscape. More light exposure will also lead to a larger plant and more blooms come mid-to-late spring and summer.
When planted outdoors in garden soil, no fertilizer is needed. However, occasional feeding may be required indoors. Use a well-balanced fertilizer and let the plant tell you when it needs food—if its green color starts to pale or it doesn’t flower, it should be fed.
In order for the prickly pear to thrive, it needs to be planted in well-draining soil. Your best bet is a mixture that is dry, sandy, or gravelly, but it can also do well in a mixture that is primarily clay, so long as it drains very well and the soil does not retain much moisture. When it comes to pH levels, prickly pear isn't especially high-maintenance and can thrive in a neutral-to-acidic mixture with a pH level of 6.0–7.5.
Like any cactus, the prickly pear likes warm, dry weather. Though it's more cold-hearty than most other cacti and can survive cold temperatures down to 14 degrees Fahrenheit, it will grow larger (and bloom more) when raised in warm temperatures. Keep in mind, it needs to be kept dry, so any additional humidity (like misting the plant) is unnecessary.