Fruitless trees can still sometimes create produce

Question: I read a small article online that you wrote about fruitless olive trees. We just had two new 36-inch box fruitless olive trees planted in our front yard. We noticed about a dozen green olives growing at the top areas of the trees. Our landscaper told us that even fruitless olive trees can get some olives but not enough to be a problem or a mess. Should we feel comfortable with what he is saying, or will these trees eventually end up producing a large quantity of olives?

Some olives, even though they are supposed to be fruitless, will still produce a small amount of fruit. It's kind of like how the purple leaf ornamental plum is supposed to be fruitless as well. This does not mean, however, that they are pollenless. They still produce some pollen if they also produce some fruit. So watch them closely. If the fruit load gets bigger each year, you may have a problem.

There is one more possibility. These olives are grafted or budded onto an olive rootstock. If the olive rootstock has taken over and beat out the budded fruitless type, it is possible it will be a fruitful form.

There is no way to really tell unless you can see this happened at the bottom of the tree where the grafting or budding was done. Because this happened at the nursery, the landscape company would know nothing about that. And the nursery that was growing the tree, because its labor is generally unskilled, would not have known it, either.

If you see an ever-increasing amount of olives coming from the tree in the future, you might elect to have it replaced to remove future problems or learn how to brine olives or make oil.

Bob Morris is a professor emeritus in horticulture with the University of Nevada and can be reached at extremehort@aol.com. Visit his blog at xtremehorticulture.blogspot.com. For more gardening advice, see the Home section of Thursday's Las Vegas Review-Journal.