How can I tell when it is ready?
As soon as the silks appear.
That's about it... otherwise you just end up with fairly naff tasing cobs... :-X
Thanks for the replies. I had a feeling I had left them too long! Ah well! I picked them today and have about 20/100 that look good. Still I have 20 and now I know for next year.
If it's any consolation, I made that mistake last year too!