Posted: 23/05/2014 at 15:32
Yes, I know what you mean, I am a trained Horticulturalist and have been gardening for over forty years. Some people get snippets of advice here and there and it is right in context but not always the broader picture. A bit like a blind man describing an elephant from behind. Sometimes it's good advice if you're a professional grower or growing for show but a bit over the top if you're growing for your own pleasure. Many things will work in Horticulture and what's best really depends on what conditions you have, which is why when I give advice I try to give a rounded view. I now only work in an advisory role. Make up your own mind what you want to do. Keeping them in pots could well give bigger plants in the end but that all depends how much work you want to put in and the comparable conditions in the ground. As I said at first if you have room to put them in the ground then they will fair better with less fuss, and cutting off the flowers is really only going to make a small difference as long as you don't let them seed and even them I'd challenge you to see the difference.
As for pinching them out, they're herbaceous plants not shrubs, what a plant needs is to grow a big root system. For that it needs to get light so really pinching them out isn't going to aid that. Unless your plants are very highly messed about by breeders then I would let the plant do what mother nature 'designed' it to do. There's no 100% right answer or wrong answer though, and cutting them back could well be the best thing if they're leggy from too little light which they will be if you hide them away to stop you having to water them three times a day when it's hot.