Tried Good King Henry last year in a seed bed - none germinated. the supplier, Chiltern seeds had this to say.......
"With regard to the Good King Henry, these should be started off in the warmth and, as with all Chenopodiaceae, germination is likely to be slow and irregular and could take many months. We would certainly never advise sowing the seeds directly into the ground as we feel the extremely high losses that can be expected are far too high and we would recommend starting these off indoors in seed trays/pots."
... and sent me a free new packet to try again! Nice people :)
