The second year you are rejuvenatingovergrownoleanders, trim half of the remaining mature stems to the ground, and shorten the long shoots resulting from the prior year's growth. Achieve healthy, perfectly shaped Oleanders with expert techniques for pruning, rejuvenation, and critical toxicity safety guidelines. Oleanders which flower earlier usually finish flowering earlier, so can be pruned back in September, but it's too late in the year now to do them, especially if you've already had a frost. I have a 'wall' of oleander that is 18-20 feet tall of spindly, small width branches that I would like to turn into more of a 10ft tall bush/privacy screen. Pruning an OvergrownOleander.When you are rejuvenatingovergrownoleanders over three years, you do about one-third of the requisite thinning each year. Rejuvenate or retrain an older, overgrownoleander by cutting back 1/3 of the older stems to the ground level in autumn. To effectively trim overgrownoleander shrubs over a period of three years, begin in the first year by cutting one-third of all mature stems down to the ground. RejuvenatingOvergrownOleanders: Tips For Pruning An OvergrownOleander | Oleander plants, Evergreen flowering shrubs, Plants. Red Flowering Bush. Overgrownoleander shrubs can be rejuvenated by snipping one-third of all mature stems to the ground in the first year and half of the remaining mature ones in the second year.
