The best time to prune nandina is in winter, when it is dormant.

As far as how, the folks at Texas A&M University recommend cutting about a quarter of the stems down to the ground. Then cut a third of the total stem height off one out of every four remaining stems. Next, prune about one quarter of the stems two-third of the height of the plant. Leave the final quarter of the stems uncut. 

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Tips On Pruning

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