Bolted celeriac with dead leaves

[Mauro]

Hi, I have a celeriac plant in a planter outdoor, I thought it was doing well being maybe 60cm tall and it's gone to seed.
However all the leaves have dried out and died, the stem and bolted ends are green though, is it normal?

Cheers, Mauro

 

[Mauro]

Hi, I've attached 2 photos of the celeriac with dry leaves

. Also this is the only celeriac plant I have and it's gone to seed, do you think it can produce seeds even though there is no other plant to pollinate with around?