Just don't understand

I'm really at a loss here. I really try to tend to the garden, but I must just really suck at it. The weekend before last I planted 72 plants (annual flowers). I was out there Friday, Saturday, Sunday working on different areas. And now, this week, I go around inspecting, and there almost all gone! Ripped out of the ground, or just plain dead. What am I doing wrong? In the front, the petunas are missing (is it the rabbits, squirrels, chipmunks, the neighbors....??); in the back, I planted an entire flat of impatiens, and now, maybe a dozen, if that, are noticable. The weeds, these are doing great... taking over. And I'm gonna leave them, just so then there is some color!! And the roses, that was a big mistake. I think they're almost dead. Planted sunflower seeds... should I be seeing those yet? And the lavendar seeds, guess they were duds too. What a disappointment my garden has become. At least Ja got a new mower over the weekend, so the grass will look good. -em