I've had both grandiflora and vulgaris pollinated in my outdoor bog (not sure how)- also some OP mexi pings. I did (last year) see a hummer visit a few mexi ping flowers, so that *might* have been the culprit. I'm trying to get better at sowing ping seed, so try and keep an eye out for any forming pods. I don't always get them at perfect ripeness, and have had pods 'spill'. Practice makes perfect.