In article , Pam Moore
writes
If any of this years plants survive, how do I know when to pick the
heads? How can you tell they are ready?

Globe artichoke heads should be picked as soon as or just before they
are fully developed - if they are left on the plant any longer than
that, the fleshy pad at the base of the petals, i.e. the artichoke, will
become fibrous and unpleasant to eat. That stage can be judged by
looking at the points of the petals on the head - when they begin to
harden or to open outwards, it is time to pick the head. If in doubt, it
is better to err on the early side. The stem which carried the head can
also be taken off at that time as far down as the next branching stem
carrying another head, or to the base of the plant.
--
Alan & Joan Gould - North Lincs.