Stanley is a large purplish-blue freestone plum. The flesh is juicy, sweet, and delicious. The plum has greenish-yellow meaty flesh and is freestone. It is harvested in late summer. The tree is late blooming, extremely cold hardy and reliable. It does not require a pollenizer, and is itself a useful pollenizer. The tree is large and spreading, and starts into fruiting young. It crops heavily and reliably (late blooming helps avoid late frost). Stanley is very susceptible to brown rot, so it will need to be sprayed with fungicide in wet areas. The fruit are also susceptible to splitting after rain. The chilling requirement is 800 hours, and the tree is self-fruitful.