Now the big question - what to put in?

Still plenty of time to do courgettes and beans.
And beans will help condition your soil for next year's brassicas.

A fruit tree - have to be pot grown this time of year. A good number of
plots have fruit trees already, mainly apples by the look of them.

If other plots have them, you're probably ok, but you may want to check
you're allowed to plant fruit trees. On ours you're not meant to, but it
doesn't really stop some people. :-/ There is a lot of tutting happens.