The thundercloud plum tree ( Prunus cerasifera ' Thundercloud ' ) is a small deciduous tree that bring about eatable purple fruits in the fall . The fragrant white or pink efflorescence come along in the spring . The leafage emerge ruby red and plough reddish purpleness as it matures . Thundercloud plum tree trees originate in U.S. Department of Agriculture ( USDA ) hardiness geographical zone 5 to 8 in full sun and well - drained soil . They acquire well in acidic soil , but will also grow in alkaline soil , and are moderately drought large-minded . They are prostrate to several fungal diseases that affect the trunk , foliage and fruits .
Trunk and Branch Diseases
wretched growth and undersize leaves are the symptoms of armillaria crown and theme rot on thundercloud plum tree tree diagram . It is because of soilborne fungus that produces mats of white development under the barque of moved trees .
Crown galls are lenient spongy wart - like increase on the crown or roots of thundercloud plum tree tree . As the galls mature , they become grating and concentrated , and may girdle the trunk and kill the affected tree diagram .
The cytospora fungi forms elongate cankers on the trunks and branches of thundercloud plum trees . It is a perennial canker sore that continues growing each year and causes discolored foliage and drooping branches .
Foliage Diseases
The foliage of thundercloud plum trees can develop minor circular leafage spots . The leaf spots are purplish and twist brown as they get big . The centers of the folio spots may leave out out cause nip golf hole .
Rust causes yellow spots on the upper sides of the leaf , and browned spore volume on the underside of the leaves . The leaves appear yellow and strike down prematurely .
Leaves affected with silverleaf are ash-grey gray in color with a green jot and curl more or less . As the disease progresses , the affected outgrowth declines and die .
Blossom and Fruit Diseases
Brown - end blossom putrefaction impress the blooms on thundercloud plum trees in the saltation . Infected blooms turn lightheaded brown with buff or gray areas of spores . The disease can scatter to lowly twigs and branches .
Plum pouch disease on thundercloud plum Sir Herbert Beerbohm Tree causes misshapen ontogenesis of leaves , limb and twigs . Infected yield wrick yellow and become swollen and vesica - like .
Russeting causes blackleg to appear on the yield three to four weeks after full heyday . As the disease progresses , the shiny scabby domain form irregular bands , which turn brown and become rough .
