Posted: 24/01/2013 at 10:54
Heritage varieties are open pollinated. Tomatoes are naturally self-pollinating so you can collect the seed and grow the varieties again and again.
To produce the F1 seeds the companies will have to keep the parents from year to year if they want the same cross again. But they will eventually be superseded as something bigger and brighter comes along. Some F1s will be worth the extra, some are little better than what has been grown for years.
But do not try to grow on from seed produced by the F1 plants, you will get all sorts.