A.
Oleanders are very popular in Galveston County and the surrounding Gulf Coast
area. Once established, they give plentiful, eye-catching blooms,
sometimes as long as from late spring to the Thanksgiving season, with very
little care. Their water requirements are minimal, making oleanders an
excellent choice for the Xerotrophic low-water, or low-maintenance landscape.
Although oleanders do not have to be pruned in order to thrive and put on a good show, it is sometimes necessary to prune off excessive growth in order to maintain a neater appearance. Often the larger varieties of oleanders outgrow the site where they are planted and threaten to engulf the yard or shut off views. The resulting pruning needs to be done at the proper time or the next season's bloom may be lost. Pruning may be used to rejuvenate older bushes, or to remove leaves showing salt burn or disease.
Oleanders with a shorter blooming
time (generally spring) may be pruned any time after blooming, but before the
middle of September in our area. At this time, prune the types that have
extended bloom into the fall, so that enough time will elapse for new stems to
grow, mature and become more freeze tolerant.
On mid- to tall-blooming oleanders, keep in mind that it will take four to six months of growth for the plant to put on the necessary 12-18 inches of new stems needed for bloom production.
The popular, newer dwarf oleanders need very little pruning, perhaps just enough for thinning or shaping the bush.
It is best to develop a plan for individual plants based on the desired dimensions. Thin out some taller stems, all the way down to the ground level. The tendency to make multiple base shoots means you will have to cut these out periodically in order to maintain an attractive, multi-stemmed shape. Remove broken, dead or crossed branches. Decide on the ultimate height you envision for your shrub, then remove stems extending beyond this by cutting 1-3 feet below the desired height.
Your end product should not look as if it has been pruned. It will still be globular and have stems of various lengths.