Duranta repens, commonly known as skyflower, is a tender evergreen shrub noted for its graceful, fountain-like shape and delicate blue flower clusters. It grows best within U.S. Department of Agriculture plant hardiness zones 8 to 11, although it will die back each year in zone 8. Skyflower shrubs require routine maintenance such as yearly pruning to improve their appearance. However, it must be properly timed to keep from impacting the plant's ability to bloom in summer.
Type of Pruning
One of skyflower's most desirable traits is its graceful growth habit, which can be easily ruined by overzealous pruning. The plant should be pruned lightly to remove dead growth, thin out overcrowded branches or to control its size. The lead branches or trunks should not be pruned because the shrub will appear lopsided and lose its graceful symmetry.
Skyflower shrubs bloom on new growth, so they must be pruned at the right time of year to keep from interrupting their normal blooming cycle. Late winter is the best time to prune, but it can also be done in early spring before new growth emerges at the tips of the branches. Avoid pruning in late summer or autumn because it may prompt a flush of new growth that will not have time to ripen and mature before cold weather sets in.
Without the correct preparation, it is possible to damage skyflower shrubs during the pruning process. The pruning shears should be freshly sharpened so they produce a straight cut with minimal tearing of the branches. Also, they should be washed in hot, soapy water to remove any dirt, then sanitized to eliminate any pathogens. A bleach solution composed of 1 part bleach and 3 parts water works well, as does a 50-50 solution of half rubbing alcohol and half water. Soak the pruning shears' blades in the sanitizing solution for five minutes, rinse them thoroughly and allow them to air-dry before use.
Pruning and Aftercare
Prune skyflower shrubs to control their size by removing any suckering growth or unwanted side branches at their point of origin. Thin out any crossed branches from the interior of the crown. Any dead or damaged growth should be removed last in case it harbors pests or infectious agents that may be transmitted to the healthy branches via the pruning shears. The only type of pruning that can be performed as needed year-round is deadheading, or removing the old flowers to tidy the shrub's appearance and limit the chances of self-seeding. Simply snip off the flower cluster at the base before it sets seed and discard it into a green waste can.
Skyflower shrubs produce an abundance of slender thorns, which may cause injury to unprotected skin and eyes, and the leaves provoke dermatitis in susceptible individuals. Always wear protective eyewear, long sleeves and gloves when working with skyflower shrubs and wash your clothing thoroughly afterward. Additionally, the showy orange berries are highly ornamental yet very toxic, so they should be pruned off if the shrub is growing near heavily trafficked areas or where children or pets play.