[daveslash]

Can you cross pollinate cauliflower and broccoli (outside of genetic engineering)? I honestly cannot say with certainty, but I tend to doubt it. If you can, I would think same species; if you can't, I'd think separate. My supporting evidence is non-scientific and anecdotal - having a garden for 15 years with both plants in close proximity I would have thought if cross pollination had been possible it would have happened in that time frame.

[Shog9]

Yes. http://en.wikipedia.org/wiki/Broccoflower

Google is your friend.

FWIW, an awful lot of seed growing involves preventing unwanted crosses, but unless you were saving seeds from your garden you might overlook this.

[daveslash]

Thank you. From the wiki page, I can't tell if that's Broccoflower is the result of cross-pollination as would happen naturally or the result of direct human intervention - I also can't tell if the seeds from Broccoflower are viable - I'll Google around more and learn :-)

As for overlooking - you're right, I did and should have thought of that before commenting. After a few attempts at saving seeds it became obvious to me that buying them each season was preferable.