Every spring I weed and then thin my perennial the garden thinking "Oh, this won't be to crowded!" But look at the hostas, the ferns, spider wort, and my yellow flowers, tall flowers and other things I don't even know the name of! Talk about crowded!
In fact I cut my hosta in half and took out about a third of the yellow flowers to give to my sister when she was visiting this spring. Wow, didn't even make a dent! I think it came back stronger!