Shrubby St. John's Wort (Hypericum prolificum)

I planted 4 of these in Spring 2020 very near some walnut trees, and it is true that they are one of the few plants that can thrive near walnut trees. It is rather shady where they are, although they do get some light. I also placed cardboard around these to keep the weeds out, as there is a lot of ground ivy, etc. where they are located.