too late for a bean trench?

Made mine at the end of Sept ish,( i was bored and it seemed like a good idea) it's been filled twice with vegetation and stuff, now its full of water 

Fill it with coy carp richie.  You know, the shy ones that taste delicious.

You can put runner bean seeds directly into the ground in mid-may, or plants at the end of may.  Dig a trench approximately in the middle of April, line the base with old newspapers and cover with manure, backfill and leave to settle.

This will assist in water retension and give good rich soil. Good Luck.