How much spacing is required to plant a blue prince/princess holly hedge?
I have clay soil
Planting along a foundation.
Once obtained as a hedge can I use a hedge trimmer to get the shape required? or
If I get more mature hollies can I plant closer together to achieve a hedge using a trimmer?
Thank-you for contacting the Toronto Master Gardeners with your question.
The situation you have in mind for your hollies seems to be appropriate. The one possible problem is the shade. The ‘Blue Prince/Princess’ hollies, Ilex x meserveae, prefer full sun to part shade. Deep shade could lead to lanky growth which could be unattractive in your foundation planting.
I am including a couple of internet articles to assist in your research on these hollies. The first provides some general information about their cultivation.
You can use a spacing of between 18 and 24 inches, depending on the size of plants and the effect you wish to achieve. Smaller plants generally establish better than larger ones. Within a few years, if they are healthy, they can overtake the plants that started off larger.
Below, you will find a link to a good article from Fine Gardening Magazine which will inform you about the best time to prune hollies and give you specific pruning instructions. While indeterminate hollies, such as the Blue Prince/Princess cultivars, can take on a formal shape and fairly aggressive pruning, it is often more effective to prune with secateurs (unless the size of hedge precludes this).
I have included two of our gardening guides below which recommend plants that may fit better with your shady spot.
Ornamental Shrubs for Various Light Conditions: A Toronto Master Gardeners Guide
Evergreens Suitable for Hedging: A Toronto Master Gardeners Guide