I have two Virburnums, one is a Viburnum trilobum and is in the back yard and the other is a Korean Spice and that one is out in the front yard, more or less as a specimen shrub. I know that both of these shrubs should be growing berries in the fall, do I need particular shrubs to pollinate them? If so, what would they be?

When I purchased the Koren Spice, the guy at the garden center told me that the shrub does it on it's own but I tend to be skeptical.

Thanks!

Linda