Answer: Old growth will be evident on your hydrangea next spring. To encourage new growth and new flowers, prune your hydrangea down to about 18" above soil level next March. The old stems will develop new flowering shoots. Your butterfly bush can also be pruned down in the spring, to encourage new flowering growth, but it can simply be pruned all over, or you can prune it all the way down to ground level. The important thing to remember about your hydrangea is that you will need to maintain at least a few of the oldest stems each year so that it will flower reliably each summer. Hope this clarifies things for you.
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