Cilantro will eventually die out even if you pick off the flowers. Same is true with chives. There are several recent posts here about all of the herbs you mentioned.

Oh, heck, why remove the flowers when they are so beautiful - and so many of them are edible too! Flowers don't kill plants. Mind you, some annuals will flower soon before dying - but it's not the same thing, is it?

Most of my herbs (the popular culinary, so-called Mediterranean ones especially) flower almost all year round. It's wonderful! I just let it happen, and enjoy them. (I live in the subtropics where the climate suits these herbs perfectly.)

oregano - just doing what it does best! Leave them.

tarragon - not the real French tarragon, maybe? Leave them.

parsley - it's 2 years old and about to die. Remove the entire plant and start again. But if you leave it to its own devices, it may very well self-seed. Just what you want!

Lavender - it's the flowers you want for culinary, medicinal, cosmetic, perfume (etc) uses. USE THEM. And let the plant produce more!

sage - so pretty, so edible. Leave them.

chives - leave them, or eat them. They won't kill the plant. The plant will die down in cold weather, but it'll pop back up again in spring.

mint - the spearmint could well set seed and spread even further if you don't remove the flowers. Remove them and eat them. Ditto the chocolate mint with regard to the eating thereof.

basil - I remove the flowers only when the plant becomes top-heavy and threatens to lift itself out of the ground. I have never noticed the slightest difference in the flavour of the leaves with or without basil. Some people say the flavour changes when it flowers - if it does, my taste buds are dead! You can eat the flowers. Cutting off the flowers may encourage a bushier growth of your plant if you live in a cooler climate where it won't get to optimum size. Choose for youself.

cilantro. I call it coriander. Removing the flowers might prevent the plant from bolting, but it's unlikely. It's a very short-lived annual (in my part of the world, even in winter, it lives only 2-3 weeks). There's really nothing you can do to stop the plant from flowering so why bother? Let it go to seed and you'll end up with a whole lot more plants. You can eat the flowers.

Thanks Daisy.

Like Daisy said, flowering won't kill a plant. Also, those very pretty, tiny flowers bring in some different, and needed, pollinators; teeny-tiny ones, that then go forth and lay their eggs in/on the dastardly caterpillars who are munching your Tomatoes. So, I always let the Parsley, Coriander, Caraway and Dill go to flower. (OK, so I want the seeds of the Caraway, Coriander and Dill.)

Plants like Sage, Mint and Oregano should be cut quite low after flowering... sort of a rejuvenation.

I don't know that I'd let the Chives go to flower, as they will seed a lot. Unless you want Chives everywhere, or want your clump to double in size for the next year, I would cut most if not all of the flowers off.

Except... Chive flowers are lovely to use in cooking, either fresh (salad) or tossed in stirfry.

And we wonder why there are still wars? ....... EXTREME?.......Not at all! If the RESPECT! for nature was as inherent these days as it was before this imence influx of technology and self self self survival instinct, fueled by money, opinion and knowledge. (Or in most cases, the 'access' to such knowledge! Because we only watch or read about science, we do NOT understand it) We all carry awround a superficial belief that we are in some way better than a simple garden herb, when in fact! You haven't got a clue as to weather you are or not? ......If a scientist told you tomorrow that tomato plants turned into roses if you planted a leaf in a secret yet unknown composite recipie of sand soil and lime, But at the same time could risk the well being of any future tomatoe plants from growing. You,d all be having a blind try at it, would you not?.... The point being, do what you can to keep a plant alive, appreciate the nettles as you do the roses, (there's no difference believe me) love them all, whatever. And stop with the false belief that your better than a basil. And that comments posted like this do not deserve a good thrashing.