Goldenrod and Sumac


I live in the Scarborough area and have been informed that Goldenrod and Sumach that grows in the garden are noxious weeds. Can you confirm if this is so?


Thank you for your questions regarding these two native species.

Canada goldenrod, (scientific name Solidago canadensis L.) was once considered a pesky weed particularly in cultivated fields. It is a native perennial plant that is found throughout much of Ontario and can spread via seeds or rhizomes (a type of underground stem).  Goldenrod is now being recognized and enjoyed as an excellent choice for a pollinator garden as it is both host and food source to a wide array of insects, moths and caterpillars.

Goldenrod has been popularly (and incorrectly) identified as a cause of “hay fever” allergies for many people, but this is not the case. Goldenrod pollen is heavy and slightly sticky and doesn’t blow on the wind. Ragweed, which flowers at the same times as Goldenrod but has a less conspicuous bloom, is the cause of many seasonal allergies.

Sumacs (Rhus spp.) are woody plants that are also native to Ontario.  Sumacs spread by underground rhizomes (horizontal underground stems) that put out lateral shoots and adventitious roots at regular intervals. As a result, Sumacs have the potential for forming large clones (thickets).  Like Goldenrod, Sumac blooms and seeds are a food source for a variety of insects and birds.

One of the most common local sumac varieties is the Staghorn sumac, (Rhus typhina L.), which  has velvety-hairy branches, sharply and coarsely toothed leaflets in pinnately compound leaves (leaflets in rows along or on either side of the middle vein) that turn vivid red in fall, and cone-shaped clusters of red fruits.  It is not poisonous.  Poison sumac (Toxicodendron vernix) has a similar leaf arrangement but they are usually smooth-margined.  It develops clusters of white flowers followed by whitish berries. Poison sumac is typically found in wetter areas (wet woods and edges of swamps and lakes). The entire plant is poisonous.  It is less likely that you have this sumac variety in your garden but if you would like to share a photograph with us we can help to determine this for you.

The question of whether or not you need to remove these plants depends on whether or not you like their appearance.  Both plants can be an attractive addition to gardens and landscapes, with the benefit of also being native to our region and providing a necessary host and food source for pollinators.

You may also be interested in Master Gardening Guide on Pollinator Gardens found at: