We have 4 multi stemmed phantoms
about 5 feet apart , western exposure under filtered light from deciduous and pine trees..They are 5 years old. I’d like to prune them. Could I cut branches close to main stems in order to encourage new shoots in the center of Bush ?
Dear Gardener, thank you very much for asking this question on pruning your Phantom Hydrangeas. The pruning of hydrangeas is a common question posed to the Toronto Master Gardeners, since when to prune — and whether to prune — is very particular to the type and even the cultivar of hydrangea.
The general guideline on hydrangeas and when to prune them comes from this site. https://plantaddicts.com/pruning-hydrangeas/.
In general, the site writes:
(1) All dead stems should be removed from hydrangeas every year.
(2) After the plants are at least 5 years old, about 1/3 of the older (living) stems can be removed down to the ground each summer. This will revitalize the plant.
(3) In addition, if it becomes necessary to prune a plant to reduce its size, it may be cut back in June or July without harming the next year’s bloom. But it will return almost immediately to its former size. This is one reason why it’s best to plant a hydrangea where it does not have to be pruned.
The HYDRANGEA PANICULATA ‘PHANTOM’ has a woody stem. It is the one kind of hydrangea that can be pruned into a tree shape. Pruning no more than one-third of any stem is the general guideline for all pruning. However, the Panicle Hydrangea is very responsive to all pruning, so pruning the side stems is possible, especially if you are hoping to prune your plants into a tree shape.
The Panicle Hydrangea blooms on new wood. Pruning can be done in the late Fall when all the leaves and the flowers have turned brown, or in the early Spring. Pruning in the Spring is more desirable, as outlined in this video, so that you have the attractive dried flowers to look at during winter. https://www.youtube.com/watch?v=0zGP3zaGL_M.
The Toronto Master Gardeners get lots of questions about hydrangeas. On the home page of our website, type ‘hydrangeas’ under ‘Find it Here’ to see a list of previous questions on this topic.
Best of luck and lots of big beautiful blooms on your hydrangeas!