….in my sunny backyard in downtown Toronto.
I want know what it is, does it flower, is it invasive and how much room should I give it….
Hello – I believe your plant is Canada Goldenrod (Solidago canadensis), a tall (up to 6 feet) native perennial. If you look carefully you can see that the leaf edges are sharply toothed which is a distinguishing characteristic of the plant. Also, the leaves lack stalks so attach directly to the stem.
Canada goldenrod is widespread in Canada – you may well be aware of it. It has a bad reputation for causing allergies but in fact the allergies are caused by wind-pollinated plants (ragweed!) which golden rod is not. In late summer into the fall, it will produce a branching flower head consisting of many, small yellow flowers. It loves sun and is drought resistant.
While native plants by definition are not considered invasive, this one spreads aggressively by both seeds and running rhizomes creating large clumps very quickly. Some sources classify it as a weed. In my own urban garden I do treat it as a weed and pull it out. I grow several other goldenrod species. At my cottage, Canada goldenrod is welcomed.
Goldenrods are outstanding pollinator plants. The City of Toronto has put together a Fact Sheet to encourage their use in Toronto gardens. The Fact Sheet notes that there are more than 25 species of goldenrod native to Ontario so ‘there’s a goldenrod that’s right for every garden’. I’ve included a link below to the Fact Sheet.
Enjoy working with goldenrod in your garden!