Purple Flowering Plum - Disappearing From Las Vegas Landscapes

Purple Leaf Flowering Plum (Prunus cerasifera)

During the past twenty-five years we have seen a tremendous decline in the purple leaf flowering plum trees across Southern Nevada.  The losses have been primarily due to the insect the flat head borer.  Today flowering plum is used in limited quantities in commercial landscapes with most tree installations occurring in residential landscapes.  The flat headed borer will continue to thrive in Southern Nevada and many more plums will be lost each year, especially trees that are stressed due to adverse cultural or environment factors. 

Keeping trees strong and healthy through good cultural practices including fertilization, irrigation, pruning, and pest control will greatly reduce problems with borers.  Trees should be fertilized mid to late February, late spring, and again early fall.  Irrigation system design should meet the needs of newly installed trees as well as meet the eventual requirements of a mature tree.  Trees should be professionally pruned each winter to ensure good structural development of the branches that form the crown but should also encourage good density.  Excessive thinning may promote sunscald of the internal branches which will encourage borer infestation. 

In addition to borers, purple leaf flowering plums are attacked by chewing-type insects and foliar diseases.  These pests along with poor cultural practices reduce leaf size thus increasing potential for sun scald of internal branches within the crown.  Proper cultural practices including fertilization in conjunction with two foliar applications of an insecticide/fungicide mix will greatly increase leaf size and overall density of the tree’s crown.  The insecticide/fungicide mix should be applied to the tree’s branches and foliage following spring bloom with the second application six weeks later.