The best time to prune oleander is in autumn. To protect your plant against the cold, bring it indoors during the winter months. You can also prune these plants in the spring, but this will affect flower formation, providing you with fewer or no blooms.

To ensure the vitality of your oleander, prune at the appropriate time. Because they have a very short bloom time, the best time to trim oleanders is right after they bloom. For varieties that bloom well into the fall, it is imperative to have them trimmed by mid September. Having the right tools makes pruning oleander shrubs easier.