I'm a new gardener with a new garden - we bought a brand new house in 2003 which is built on what was one time a corn field. Hence no plants at all. We now have grass in the backyard along with some flower beds but it still looks pretty boring. I was thinking to put forget-me-nots in one of my flower beds and read that they often self sow. I'd like to have them year after year without replanting so I like self sowing part. On the other hand my sister-in-law who has an old garden (30+ years) complains that they grow everywhere in her yard and she lost control over them. My question is - how do you prevent them from self sowing? Oh, and I'm in Zone 5 if that helps.