Pruning an Overgrown Oleander
The good news is that you can do rejuvenation pruning of oleanders and get old, overgrown plants back into shape. You’ll have to evaluate the health of the oleander shrub and determine if it can withstand drastic pruning all at one time. The problem with one severe pruning is that it can induce excess foliage growth and encourage basal sprouting. If the plant is in fragile health, its vigor can be reduced and a very weak plant may even die. When you consider pruning an overgrown oleander severely, you may be better off to do it little by little, over a number of years. When you are rejuvenating overgrown oleanders over three years, you do about one-third of the requisite thinning each year.
How to Trim Overgrown Oleander Shrubs
Generally, you’ll want to keep a shrub’s natural shape when you start pruning, even when you are pruning an overgrown oleander. The oleander’s natural shape – a clumping-type shape – is almost always more attractive in oleander hedges and screens. Here are tips for how to trim overgrown oleander shrubs over three years:
The first year, snip one-third of all mature stems to the ground. The second year you are rejuvenating overgrown oleanders, trim half of the remaining mature stems to the ground, and shorten the long shoots resulting from the prior year’s growth. The third year, trim back the remaining older stems to a few inches (8 cm.), and continue heading back new shoots.
When to Prune Oleanders
Generally, the time to prune most spring flowering shrubs is late summer or autumn, or just after blooming. This gives the plants a chance to develop the new growth on which next season’s blossoms will grow. However, summer flowering shrubs, like oleander, should be pruned in late winter or spring. Don’t prune in fall or mid-winter since this encourages frost-sensitive new growth.
