While best known for their stunning blossoms in spring, Thunderhead Flowering Plum trees do in fact produce a small fruit. It is a small, red-purple edible plum, but it does not compare to plums in supermarkets. These small fruits are best used to attract birds and wildlife to your garden, or to incorporate in a small chutney or jam potentially. Be sure to plant your Thundercloud plum tree a good distance away from your driveway since these small fruits will fall and will stain surfaces.