Q: I was told that there are male and female trees.

Female trees are more expensive and more people are buying male trees which give off more debris.

Is this true or a joke? A Horticulturist on TV was supposed to have said this.

A: It's true, there are cases of male and female trees.

These are called dioecious trees (versus monoecious trees, which bear gametes in separate flowers on the same plant and are self-pollinating, e.g., crabapples). Dioecious trees include ginkgo and holly.

With dioecious trees, both a male and female must be near enough to each other for the female to produce fruit.

In the case of the ginkgo, this is NOT a desirable event! The fruits are messy, and if they sit around long enough they can be extremely pungent, and I am NOT talking rose-like (putrid would be a good description).

In the case of hollies, the fruit IS desirable, so we like having both genders around each other. You only need one male plant to accommodate up to 10 females.

Some trees, like mulberry, are polygamo-dioecious, meaning they can be either male or female. Mulberry, in fact, will sometimes switch from one gender to the other (please don't ask me why!)

As for debris, the female will likely cast off more because she produces all the fruit.

As for expense, my price check didn't come up with a difference between male and female plants, although with the ginkgo it would be worth a few extra dollars NOT to get a female (due to the nasty fruit!).