My serviceberry bears fruit all by itself; I don't think that there is another one nearby. I've got a viburnum trilobum that gets berries, and I don't have another one, but there are a lot of different viburnums within several blocks, so it could be that something else is near enough for pollination.

ps-you will be amazed at the serviceberry; this spring I had 20 cedar waxwings in the tree at one time; the only time of the whole year that I see them is when the serviceberries are ripe.

Cross pollination is never an issue for flowering but many fruiting plants set more fruit thanks to cross pollination.

It is not documented as an concern for Serviceberry as much as it is for viburnum. The key is to have them flowering at the same time. For viburnums, I get a good fruit set between two adjacent ones - mapleleaf viburnum and arrowwood viburnum (Viburnum dentatum) because they flower together. I think almost any combination is good if they are flowering at the same time (that is the tricky part).

The good thing about Viburnum nudum is there are so many cultivars available that you can find them in the nursery trade. And you can pick up a species one at a native plant sale. Just don't get two of the same cultivar (e.g., two 'Winterthur') since they are genetically identical and would not help with cross pollination as a result.

Raintree Nursery, which sells serviceberries to people wanting to grow fruit, lists them as self-fertile.

I know V. trilobum is self-fertile from personal experience but it is also listed as self-fertile at Raintree.

FataMorgana

monoicious plants have male and female flowers on different plants (ie, there are male plants and female plants)...both are required for fertilization and fruit set. dioicious plants have both sex flowers on the same plant so it can fertilize itself. if you look a plant species up on the net (wiki or elsewhere) you can find this info and know if you need more than one or not to get fruit. your local nursery person should be able to tell you as well.

But cross pollination has nothing to do with being male and female.

I should say "when it comes to viburnums". Obviously when it comes to male/female plants (like hollies), it is very important.

All the fruit nursery places use the phrase "self-fertile" to indicate that a plant can set and produce fruit without others of its kind around for cross-pollination.

As I said above, both V. trilobum and serviceberries are noted as being "self-fertile" at one of my favorite nurseries specializing in fruit and other edible plants.

FataMorgana