after my oriental poppies have bloomed shouldd I cut back the stems

Yes, unless you want millions of seedling all over the place. With a bit of luck and some rain, they will flower again in a few months time. The flowers are often smaller though, second time around.

I agree with cutting them back, you will at the least get a nice clump of fresh green leaves. Mine have never self-seeded, and I rarely get round to cutting off the pods myself!

Agree wiry Owdb. :)

We have a lot of self seeded ones when I did not get round to cutting them back.

many thanks for your help.