I am wondering how best to handle a deciduously shaded ravine forest garden being seemingly overtaken by an unknown species of perennial Elephant Ears. I gather some are edible, and some are poisonous.
While visually dramatic they would seem to be at odds with prudent native planting ravine stewardship ? These seem to spread rhizomally so the neighbours have expressed concern as well. They are flowering now. I have attached a photo (and can provide other pics) from last fall with thanks for any assistance…
Thank you for contacting the Toronto Master Gardeners. Common names can be confusing. This plant is Petasites japonicus an alien plant (an Asian native) that can escape gardens, as you have found. Despite its elephant-ear appearance, its common names include butterbur (sometimes butterburdock) or giant coltsfoot.
In milder areas of North America, such as the Pacific Northwest, it is considered invasive, a noxious weed, or potentially invasive. With climate change, it’s possible that it will be added to the watch-list for Ontario, too. They can be difficult to eradicate. In a ravine setting, it would be best to repeatedly dig up the roots.
In a garden setting, they can be used if contained, such as in a sunken planter.
Parts of the plant are edible, and parts are noxious. The leaf petioles (leaf stems) are prepared carefully and used in Japanese cuisine, where they are knows as fuki.
I hope you’ll find this helpful. Good luck with your control efforts.
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