Is it typical for Othello to be invasive? One orignal plant has turned into hundreds of enormous plants with 1-foot leaves in my downtown Toronto garden. The seedlings grow up everywhere -sun , shade, wet, dry including in cracks in the paving, the foundation of the house etc.
Thank you for contacting the Toronto Master Gardeners with your question. Although Ligularia dentata cv Othello is not considered invasive and can sometimes be quite difficult to grow well, I recently read a report about a gardener who had a problem similar to yours with plants that were shooting up as far as 30 feet away from the others. The Ligularia dentata thrives in moist rich soil. If you are fertilizing or watering the area you might wish to consider stopping while you try to eradicate the problem. To slow the spread, first prevent the plants from setting seed. Then begin by digging them out as best you can. You should also try to mulch the area to prevent seedlings from emerging. If the roots have worked their way throughout the area you may have to clear it and then start over once you are certain the invader is controlled.