Canadian goldenrod Solidago Canadensis

Canadian goldenrod Solidago Canadensis

Canadian goldenrod has remained a popular garden plant since its introduction to the UK in the 1640s. The plant is often confused with the native goldenrod (Solidago virgaurea) both being distinctive herbs with yellow flowers which form pyramidal flower heads. Both native and non-native are commonly found on waste land, by roads, rails and along river sides. Despite their similarities, there are some key differences which can help you distinguish between the two:

1. Canadian goldenrod reaches heights of up to 2m, whereas the native goldenrod has a much shorter height between 5 – 70 cm.
2. Canadian goldenrod has smaller flowers (less than 5mm across) compared to the larger flowers of our native goldenrod (6-10 mm).

In its native range, North America, Canadian goldenrod is considered an economic pest. The plant can form dense stands which out-compete native vegetation and are problematic to remove. Like the more famous Japanese knotweed, this invasive can spread through its rhizome which are resistant to fire and escape grazing. Furthermore, it can spread by seeds which remain viable for many years.

As with many invasive plants, there are management options for this species but they take time and effort to ensure you do not exacerbate the infestation. Canadian goldenrod is known to be palatable to grazing stock, however the plant usually invades habitats where this is not an option. Any mechanical removal should be carried out with extreme care as you may unintentionally spread the plant through contaminated material and equipment.

You can record this invasive plant using the RINSE app ‘That’s Invasive!’ The app also contains useful information to help you distinguish between this invasive goldenrod and the native.

References:

http://www.nonnativespecies.org/factsheet/factsheet.cfm?speciesId=3323

Images: Canadian Goldenrod (R Pls Group), Canadian Goldenrod (GBNNSS)