Don’t get me wrong, I’m happy that the public parks are using more native plants or even nativars (cultivars of native plants), but the sheer number of the same species planted together throughout the GTA sets off warning bells for me.
Even if serviceberries are native, planting them en masse isn’t ecologically healthy. A native species doesn’t exist in a vacuum. Serviceberries are a part of plant community of interconnected species that have grown up together. In other words, there must be biological diversity in a healthy community. It’s important.
Lack of diversity in any environment leaves our tree cover vulnerable to being wiped out by insect infestations or disease. It’s happened in the past and it’s still happening today: Remember American elm, and the Dutch elm disease? American elms used to be a dominant urban tree in Canada and the United States, but are now virtually extinct. Look at what is happening to the numerous ash trees in the Great Lakes area: they being decimated by an insect borer. We should be learning from this.
Instead of just planting serviceberry, add other native plants (if native planting is the preference). Serviceberries thrive in full sun to partial shade, in well-drained clay or silty soil. Other trees that thrive in these conditions include white ash (Fraxinus americana), red oak (Quercus rubra), Virginia creeper (Parthenocissus vitacea), wild columbine (Aquilegia canadensis), common wood sedge (Carex blanda), and wild geranium (Geranium maculatum).
And another thing, it’s not just ecologically devastating; it’s also visually disturbing: planting stands of serviceberries on their own looks odd. The white blossoms fade on a sunny day against a pale blue sky. Serviceberry flowers need a dark backdrop in order to pop. Consider planting coniferous evergreens as a backdrop.
And using the same plant material over and over again is torture through monotony. Please, I beg of you, try using other plant material or mix and match serviceberries with other plants. Not only will the landscape be ecologically sound but it will also uplift everyone’s spirits with a botanical vision of beauty.