Erigeronium canadensis
Annual Horseweed
- Annual or Biennial
- Average to slightly rich or slightly dry soils
- Full sun to light shade
- 36" to 60” tall, 12” to 18” wide
- Summer Blooming. Spring seeded plants often start to flower later and bloom into the fall.
- Native to Ontario, Beginner friendly, Meadow to dry meadow or open woodland ecosystems
A beautifully architectural species but, given their abundant seeding, probably not for anyone who enjoys large, open spaces in the garden (if you've read many of the plant profiles I've writen, you have probably figured out where I fall on the whole ‘space between plants’ aesthetic).
Like a lot of native annual species, these can actually develop as a rosette of leaves in the fall and then complete their lifecycle the following year, but they don’t REQUIRE a cold spell between germinating and reaching the blooming and seeding stage of their lifecycle, so they are also perfectly capable of growing as an annual.
Individual plants tend to develop a long, vertical stem with limited, if any, branching that can grow to over 6’ in a rich setting or remain as low as 18” in more lean soils.
I’ve mostly seen them thriving in settings where they receive several hours of direct sun each day and they seem unbothered by summer dry spells.
Their flowers are very, very tiny compared to most Fleabanes, not much more than a millimeter in width and a couple of milometers in length. It is their form and foliage that creates the eye-catching effect in the garden or landscape.
They do share an adaptation to disturbance with Fleabanes though, generally appearing in locations where the perennial plant cover has been removed or disturbed. Doing that annual thing of showing up on short notice to protect the exposed soil and keeping everyone fed while the ecosystem recovers.
If you enjoy spicy flavours, you might want to give a few leaves of this species a nibble or try them chopped and sprinkled over a dish, like you might with chives or fresh herbs. Be warned, though, that their heat increases with chewing, so start with a small bite, rather than a large one.
