Hi "Dream", I sort of answered your question under the Maples in MB posting, but I thought I would reply here as well.

I am sorry but I am not sure. I know that though some plants are supposedly "self-pollinating" they do benefit from having another plant to cross pollinate with. But, that can't be another tree of the exact same variety.
I think my sour cherry tree is like this. It's supposedly self fertile but produces loads of blooms and very few cherries each year. I feel if I had another cherry tree to cross-pollinate with it, it might produce loads of cherries.

As for barberry, I am not sure. I have the cherry bomb variety. It looked neat in spring with it's greenish/yellow blooms contrasting with the purple foliage, but didn't produce any berries at all. But, since my barberry is a hybrid cultivar, it could be that they don't produce berries as reliably.

Glen

Hi Glen,

I do have another Barberry that I bought a few years ago. It seems to be exactly the same and has never produced any berries. So are you suggesting I buy a different type of Barberry? Thanks.

Bonnie