Hostile Takeover

There has been a takeover in the garden while I was gone. Not only by weeds but also by some native plants that I planted a couple of years ago. I have been trying to get rid of them all year with no success. I've tried weed killer (2 different kinds) and pulling them, that's hard though because you don't want to squish snails. Don't ever plant Evening Primrose or Four o'clocks. I hope anyone who I have given them to will forgive me.