Ask Mr. Smarty Plants

Unfortunately, your description "native dogwood trees" is not precise enough as our Native Plant Database indicates that there are 5 different dogwood species native to Georgia.

Cornus alternifolia (Alternateleaf dogwood)

Cornus amomum (Silky dogwood)

Cornus drummondii (Roughleaf dogwood)

Cornus florida (Flowering dogwood)

Cornus foemina (Stiff dogwood)

Following these links to detailed plant information pages will help you identify which plant you have.  All these can develop into small trees but I suspect you have the most popular: Cornus florida.

Unfortunately, without seeing the plants, we can only hypothesize why your trees have not produced berries.  I assume they have been flowering or you would have mentioned that, so the problem is that the flowers are not being fertilized or the fruit is failing to develop.  Dogwoods are not dioecious the way hollies are, so the lack of a male/female is not your problem. 

With the declining bee population, pollination could be a problem, especially if the plants flowered very early before there were many pollinators around; but that is not likely to happen in four consecutive years.  More likely the problem is that the fruit is not setting or developing due to conditions or tree health.  Anthracnose in flowering dogwood has been a serious threat to this beautiful native tree.  It is more of a problem to trees in their native setting (shady, moist conditions) than in sunny, drier suburban lawns.

We recommend you contact your county agricultural extension service once you have identified your trees.  A phone conversation with an agent describing your trees and their situation will likely bring you an answer more easily than we can provide clues. They will be aware of problems that other homeowners in your county are experiencing.