I am interested in growing hydrangea on my condo terrace.
However I would like a small mop head variety in a size that reaches a maximum height 18″. Or is there a similar type of plant that flowers like the hydrangea?
Thank you for contacting Toronto Master Gardeners.
When picking a plant for a balcony there are several things that need to be taken into account.
When choosing your hydrangea you will need to consider the light and wind levels you have as well as whether you are trying to overwinter the plant.
If you hope to overwinter your plant you will need to consider what type of pot you pick as well as choosing a plant that can withstand colder temperatures. As you move up a building you have changing micro-climates to deal with. On the balcony, the plant will be exposed to freeze and thaw cycles that can kill it. You will need to consider pots with insulation and pots that will not crack with the temperature change.
There are two main types of Hydrangeas. Many of the hydrangeas you see growing in yards in Toronto bloom on new wood that grows each spring. This means that if there is any die back in the winter you still will have growth and blooms the following year. Many of the hydrangeas you see sold around Easter in stores bloom on wood that was grown the previous year. That means if there is any winter damage you will have no blooms the following year. I believe the mop heads you mentioned are often ones that bloom on last year’s growth; overwintering in this case would be more complicated.
Your best bet would be to assess the light and wind levels you are dealing with and decide if you will be overwintering the plant on your balcony. Once you have made those decisions a trip to your local nursery will allow you to see what plants are available and which one best suits your space and needs.
I am including links below from our library on Hydrangea species and balcony gardening.