I’m looking for ground covers which are:
– flowers in summer (like Chrysogonum virginianum) or fall (like Solidago flexicaulis)
– white or pale pink / pale blue flower colour
– part to full shade
– no more than 1′ tall
– preferably native to Ontario and can be naturalized
You have provided a very challenging set of specifications. I’m afraid I haven’t been able to identify groundcovers, native or non-native, that meet all of them. The hardest characteristic to find are groundcover plants that bloom in the summer or fall. I will make some suggestions of plants that will meet most of your requirements and thrive in the conditions you’ve specified.
Here are some suggestions for native plants that make effective groundcovers.
Wild Ginger (Asarum canadense) is an excellent native groundcover growing to just 6 inches with large, heart-shaped leaves and it spreads rapidly in part to full shade. It does prefer a moist soil. In my dry shade garden, it droops in dry spells but comes back as soon as it’s watered. It has an unusual, maroon flower that grows close to the ground so hidden by the leaves – not what you’re looking for. However, I think wild ginger could be combined with other natives such as western bleeding heart, to provide interest and more of the colour palette you are after.
Western Bleeding Heart (Dicentra formosa) like wild ginger does well in part to full shade and prefers a moist to average soil. It has pink, heart-shaped flowers in small clusters that stand up above the lacy foliage that bloom in late spring into summer. It’s a little taller – 8 to 18 inches. The height, bloom colour and textural foliage are all a good contrast with wild ginger and like wild ginger it spreads rapidly.
Two other natives I considered but didn’t make my short list are: Wild Geranium (Geranium maculatum) and Big-leaved Aster. The lavender flowers of wild geranium appear in late spring into summer which could work for you but it’s overall height is 12-24 inches. Big-leaved Aster (Eurybia macrophyllus) has very, large basal leaves which stay low to the ground. It produces white flowers in the late summer into fall but the flowers are infrequent and to a height of 2-5 feet.
For other native suggestions, I’m including below a link to the ‘Grow Me Instead’ guides produced by the Ontario Invasive Plant Council which has a groundcover section listing native plants to use as alternatives to common garden plants with invasive tendencies.
While you’ve indicated a preference for plants native to Ontario, I’m going to offer two non-native suggestions that are both outstanding groundcovers for part to full shade and are effective in woodland gardens. However, if you live close to a natural area, native plants are always the better choice.
Red Barrenwort (Epimedium x. rubrum) In his book ‘Making the Most of Shade’, Quebec author Larry Hodgson states ‘This plant might just be the best groundcover ever!’. While the numerous small flowers with red sepals and creamy white petals bloom in mid to late spring, the lovely heart shaped leaves have year round interest. The leaves are overlaid with red in the spring and mid-green thru the summer. They take on a reddish tinge in the fall which could work for you and persist through the winter. I have lots of this plant in my garden and I find the overall bloom and foliage colour is pink than red. It grows to a height of 8-12 inches. They are not fast spreaders so they are best planted about 10 inches apart. They thrive in part shade and will put up with full shade if kept watered. They will spread more slowly in full shade.
Bloody Cranesbill (Geranium sanguineum) particularly the cultivar G. sanguineum var. striatum (often labelled as G, sanguineum ‘Lancastriense’ or ‘Prostratum’) has pale pink flowers with red veins appearing in the early summer and sporadically through the fall. It is similar in height to the barrenwort and like the barrenwort, the foliage has lovely fall colour turning a burgundy red. It does like some sunlight so is best in part shade.
I hope one of these suggestions work for you or gives you ideas for other plants or plant combinations.
Jan. 19, 2022