The purple sand cherry or Prunus cistena is also known as the purpleleaf sand cherry. It is a colorful deciduous shrub, with red leaves and white spring blossoms. During the fall season, its leaves turn a gorgeous reddish purple hue. This shrub can reach a height of 6 to 8 feet, and a spread of 7 to 8 feet. Reasons to prune are to: remove any diseased or damaged branches, to control its place within your landscape, to shape the shrub, and to increase growth (renewal).
Remove any damaged or diseased branches immediately. Make a clean diagonal cut at the break or remove the entire branch (this is a judgment call on your part). The shrub does not have to be in its dormant stage---this can be done at any time that you see damaged or diseased branches.
Prune branches that are interfering with other plantings within your landscape design by making a clean diagonal cut either at the base of the shrub (if you are removing an entire branch) or at the base of another branch (if you are removing part of a branch). Flowering shrubs should be pruned in the spring after they have blossomed.
Trim any errant branches to maintain the shape of the purple sand cherry. Make a diagonal cut in front of a bud or branch. Trimming can be done after the sand cherry has blossomed, and then when needed during the remainder of the growing season.
Prune one third of older branches down to ground level to encourage vigorous growth. This should be done in the spring after the shrub has finished blossoming.