When I was weeding the other day I noticed that my white bleeding heart had seeded itself everywhere around the mature plant. My Nepeta , Six Hills Giant, also had many seedlings around it. Instead of leaving them there I potted them up in a soil-less mix ( promix ) and will let them grow in pots near my potting shed until they get big enough to transplant into my garden again. REMEMBER GROUPING Of THE SAME KIND OF PLANTS MAKE A GREAT VISUAL SPLASH. What a way to get free plants. Plants can successfully be divided now that they are through the ground.
Happy gardening. Linda