Only one bloom on my oriental poppy!
I have two oriental poppies (Turkenlouis) in my garden. They've been there for 3 summers now, growing successfully each year (expanding in size in each, dying back as predicted over the summer, etc). This year, however, and despite lush, healthy looking foliage, I had only one poppy pod emerge! One bloom only! It wasn't a particularly wet spring. Should I thin them out a bit? I know they don't like to be disturbed.
Oriental Poppy seeds need light in order to germinate. Seeds could have been covered or washed away from rain or watering.
Environmental issues may cause more or less flowers from year to year.
Here is a link to refresh you on Oriental Poppy care.