Tried this myself a couple of weeks ago and it worked - just farm a lot of seeds and try using them on grassy plot during daytime. I needed like 64 seeds to get a 4-5 red flowers (of course I got some yellow ones and pumpkins as well. So, yeah it works, but it takes some effort.
I have also heard rumors that they grow further away from spawn, like at 2000 mark, but I havent investigated that.
They do grow far out cos i went on a flower trek last night for an hour or 2 and came back with 2 stacks of Yellow and 1 stack of Red. They are rather abundant out there.