Q: On New Year’s Day a party guest raised a question I hope you can solve. Is it possible to grow an olive tree from an olive pit? We’ve grown an avocado from a pit. Why not olives?
A: An olive tree can be grown wherever winter temperatures do not drop below 12 degrees. Theoretically, that means we could grow them in Atlanta as long as they get protection from extreme cold. But I have never seen or heard of an olive grown successfully here. (This was written years ago. See the notes below!)
To answer your actual question, it’s pretty doubtful that an olive pit would sprout. There are several varieties of olives that are grown commercially. Some bear fruit that is green when ripe, others produce blackish-purple fruit. You might assume that this explains the difference between the green olives and black olives we see on grocery shelves. But, in fact, black olives are simply green olives that have been processed in such a way as to turn them black. Most tree-ripe olives are too bitter to eat out of hand. They have to be processed in successive baths of lye and salt water to give them the taste we love on our pizzas. I think the processing would prevent any hope of seed germination.