Coriander or cilantro is an annual. This means it lives only 1 growing season. With this plant, it is said to have "bolted" when blooms appear. Bolting generally means that the plant has moved into another phase of its life cycle. In this phase it will put strength into producing seeds, not foliage. The plant will die with the seeds' maturity. Generally foliage is tastier and/or more robust for harvesting prior to bolting for many things such as: lettuce, parsley, dill, basil, cilantro, etc.

Once it has begun to bolt, you can try pinching to slow the inevitable (perhaps) but it will die sooner rather than later.

FataMorgana

Yeah, if you've gotten to the flowering stage, you might as well let it continue and collect the seeds - both for planting and cooking.

I know a lot of people use "coriander" to refer to the plant as a whole, but I find that confusing. "Cilantro" for use of leaves, "coriander" for use of seeds.

I don't know what you'd use the root for.

I guess it's what you're used to, but the term 'cilantro' is never used in Australia, so it's 'coriander' or 'coriander seeds'. Doesn't get much easier than that, IMO.

To reply to the OP, you can't stop the plant from doing what it does naturally. Once it has decided to go to seed, beginning with the changing of the leaves, no power on earth or in heaven is going to reverse the process. As FataMorgana has said (and it has been said umpteen times before on this forum) - it's a short-lived annual. In hot climates, its life-span from seed (embryo) to seed (making embryos) can be as short as 2 weeks.

The answer is successive sowing to keep up a supply. Eventually you will have a little patch of plants in various stages of maturity, ensuring a continual supply of leaves - and seeds. There's nothing to stop you from eating a plant which has bolted. The taste will be somewhat coarse, however.

Entire plant is edible. Use fresh leaves and stems in salads and many Asian foods, in stews and sauces. Seeds are used whole or ground in dried in cakes, puddings and confectionery, sauces and meat dishes. Roots are pounded with garlic in Thai food, or dried and powdered for use as a seasoning. Use the stems in soups and with beans. The flowers can be added to salads.

fatamorgana:

Once it has begun to bolt, you can try pinching to slow the inevitable (perhaps) but it will die sooner rather than later.

So it's probably not worth the trouble then.

sconnielill:

I know a lot of people use "coriander" to refer to the plant as a whole, but I find that confusing. "Cilantro" for use of leaves, "coriander" for use of seeds.

It does get kind of confusing. :)

daisyduckworth:

The answer is successive sowing to keep up a supply.

Even when it starts to get hot?

Roots are pounded with garlic in Thai food, or dried and powdered for use as a seasoning.

Should the roots be peeled and/or cooked?

Also, in an article I found with a Google search, it says that when you want the roots, you should "harvest whole, mature plants." What does that mean? Before the plants have bolted?

ESPECIALLY when it starts to get hot! In hot climates, it's a winter herb. But I gave up on it even in winter, here in the subtropics.

Scrub the roots free of dirt, allow them to dry out, then put them through a food processor until powdered. You can also dry them in an oven - set to lowest possible temperature, then leave the roots on an oven try until they are dried out - make sure to leave the oven door slightly ajar.

Harvest the 'whole, mature' plant when you see the first signs of a flower, or a change in some of the leaves.

daisyduckworth:

Scrub the roots free of dirt, allow them to dry out, then put them through a food processor until powdered. You can also dry them in an oven - set to lowest possible temperature, then leave the roots on an oven try until they are dried out - make sure to leave the oven door slightly ajar.

Does it taste very good?

Harvest the 'whole, mature' plant when you see the first signs of a flower, or a change in some of the leaves.

OK, that makes sense--thanks. Also, when the plant is growing, is it best to harvest the fully developed lower leaves, or the thin, feathery leaves on top?

IIRC, thin feathery leaves only appear when it's bolting. I believe all the leaves will change flavor during the bolt stage, so use both.

Funny story - the first time I grew cilantro in my garden, my mom didn't know about bolting (to be fair, neither did I). She looked in my garden and saw a tall feathery plant growing right through the middle of my precious cilantro. She thought "OH NO" and helpfully pulled the weed for me. When I got home from work, I found my poor little cilantro wilted and lying in the dirt after baking all day in the sun.

IIRC, thin feathery leaves only appear when it's bolting. I believe all the leaves will change flavor during the bolt stage, so use both.

OK, thanks, sconnielill.

Funny story - the first time I grew cilantro in my garden, my mom didn't know about bolting (to be fair, neither did I). She looked in my garden and saw a tall feathery plant growing right through the middle of my precious cilantro. She thought "OH NO" and helpfully pulled the weed for me. When I got home from work, I found my poor little cilantro wilted and lying in the dirt after baking all day in the sun.

LOL. That's too bad. I guess she never forgot what bolting cilantro looks like. ;)

the thin feathery leaves taste like poop and are an indicator that the whole plant will do so shortly... in my area (virginia) i tell my plant customers they can only grow cilantro successfully for a couple of months in late spring and a couple of months in early fall...

i always let my cilantro plantings stand to produce seed though (coriander in my experience- obviously the semantics differ from place to place)... freshly ground coriander is incomparable to store bought... so citrussy and fragrant..

the thin feathery leaves taste like poop and are an indicator that the whole plant will do so shortly... in my area (virginia) i tell my plant customers they can only grow cilantro successfully for a couple of months in late spring and a couple of months in early fall...
i always let my cilantro plantings stand to produce seed though (coriander in my experience- obviously the semantics differ from place to place)... freshly ground coriander is incomparable to store bought... so citrussy and fragrant..

Thanks for the info, biscgolf.