Those huge heart-shaped leaves look like a brunnera plant, a shade loving perennial that often comes with silver or silver and white striped leaves as well as the variety with green leaves that you have. I would keep the hitch hiking brunnera (also known as Siberian Bugloss) as this plant sprouts delicate blue flowers in the spring. The leaves will die back in the winter once frost hits. Brunnera likes similar conditions as rhododendrons so be sure to water when soil is dry. It will do well in your shade garden. Keep growing, Marianne Binetti