Answer: Oleander does not require pruning, but you can trim it back if it gets rangey or out of control. If your plants need pruning, do so in the spring when new growth begins is the best time, although you could still prune now, as it is such a vigorous plant. You can cut the stems back by one-third. Trim back to another major branch or stem, don't leave stubs. Sometimes oleander is used as a screening hedge and is trimmed annually with hedge trimmers. Either way, oleander will react to pruning by developing new stems and foliage. Note that all parts of oleander are poisonous, and some people develop severe reactions. Wear protective clothing and I'd suggest even a face mask to prevent inhaling bits of it. Never burn oleander because inhaling the smoke can also cause lung problems.
Q&A Library Searching Tips