Goji berry can sometimes take over the world depending on conditions. Just so everyone is aware of that. It will root where it touches the ground and a thicket can get huge ... and prickly.
I personally would think the smaller plants would be fine ... and much less expensive. Since I already have plants I'm not going to worry about a pollinator and hope for the best. I'd like three of the smaller size but Gurney's plants can be dinky sometimes so small may really be very small as in about 3" tall.
Someone here has grown Goji:
The thread "Anyone growing Gojiberry?" in
Vegetables and Fruit forum
