What's killing my artichokes?

I've planted various artichokes over the years. They all end up like this. This plant has done better than all the others--I actually got artichokes off of it! I'd like for my artichokes to stop dying, though.

Any idea what's killing it and how to stop it?

Does this only happen in autumn? Mine look like that right now, but they come back in spring IF I mulch them heavily enough with straw to get them through the winter, they will not take much frost.

Mine started looking like this in summer. One of the plants (that even has a "pup" of a new plant growing out of it) had already lost all it's leaves by about mid-July.

Just thinking aloud here but it reminds me of potato blight which is fungal so perhaps it is a fungus of some sort (not blight obviously), and you live in a wet area I think? There's a lot of other plants very close by so airflow isn't going to be very good and they will be competing with it. I think I would try growing one on it's own with just mulch and no other plants near it I think I have seen the same blackening on mine when I let new transplants get overrun with weeds, I may be miss remembering that so I cannot swear to it.
Another thing that might help is not letting them flower the first year

It's hard to tell but it looks like it's in the stem too?  I think I see black marks there?  If so, I'd guess it's some sort of root rot.  This plant family is susceptible to root rot.  They like a lot of water though.  Does it have really good drainage?

I just reread your post.  You said that this happens every year to your artichokes.  I would try a raised bed next year with good garden soil.  I have cardoon, which is a close relative of artichoke, in a raised bed and it's done really well. They seem to need to be watered just about every other day so good drainage is a must with them, I think.

It looks like you have been watering them top much ,or the soil is  very compacted and wet, i can tell that by the ranunculus and dandelions aroud it. The Artichokes  is  a species well adapted to dry soils, not all the cultivars are the same but i would try with improving the soil water retention, watering less, or preparing a raised bed as others already suggested.