Holly bushes: boy or girl?

Q: I have two holly bushes, each 3 years old. I have seen only three red berries on them so far. They both get small white flowers that seem to turn into a small cluster of pinhead-sized balls of a deep maroon color. Since they have the same flowers and such, I'm thinking I may have two of the same sex bushes. How can I tell for sure?

J.R., Via e-mail

A: American holly is one species that does have both male and female trees. If you have seen any red berries, then you have female trees. You can expect a good crop of red berries--if there is a male tree somewhere in the neighborhood. They look pretty much alike, except for the flowers, which you won't see until spring. I suggest you check around the neighborhood and see if the trees have berries or not. If others are getting berries, then there is a male tree somewhere nearby. I do not know how far a male tree can be effective, but it would be 500 feet or more. Your trees are still quite young, and this may be the source of the problem. They may produce more profusely, with maturity. Only time will tell.