The Hard Facts About Growing (and Spraying) Olive Trees

These blooming Mediterranean natives are true beauties, growing up to 30’ tall and spreading out nearly as far. It’s no wonder that olive trees have become California landscape mainstays, thriving in the plentiful sunshine and temperate climate that California offers up.

While we never complain about olives in a delicious tapenade or Niçoise salad, unless you have a sprawling property or plan on committing lots of time to jarring homemade olive oil – olive trees can be a major headache.

Olive fruit can be bad news for walkers – and your indoor flooring

Moderation is key, but olive trees didn’t get that memo. They produce an abundance of fruit that’s challenging to keep up with. When the olives ripen and fall from the tree, they can quickly cover the ground and sidewalks, posing a major, oily threat to those walking over them. Not only does the fruit create an increased potential for falls, but their color and oil can quickly be transferred from the soles of shoes to light-colored living room carpet.

The olive fruit fly is a serious pest of California olive trees

The olive fruit fly has been around for thousands of years, but have surfaced only the last couple decades in California. And in those couple of decades, they have cost olive farmers quite a bit! The adult fly is rarely seen, and the larvae feed on the fleshy olive underneath the skin. The damage makes olives prone to rot and premature dropping. For commercial growers, this is a serious issue. In order to produce olive oil, damage level must be below 10%.

Olive tree blooms are an irritant for allergy sufferers

Many people suffer from an allergic reaction to olive tree pollen, and their symptoms can be anywhere from mildly irritating to severe. When the pollen is released – typically in May and June – those with allergies can experience respiratory symptoms like runny, itchy, and watery eyes and noses, as well as sneezing, coughing, wheezing, and all sorts of olive tree-induced discomforts. Those with asthma must exercise extra caution even in the general vicinity of blooming olive trees.

If you are a homeowner with olive trees on your property, follow these suggestions:

  • First off, plant fruitless olive trees such as the ‘Swan Hill,’ ‘Wilsoni,’ ‘Majestic Beauty,’ or ‘Little Ollie’ types. These olive trees have little or no fruit. If you are looking for landscape appeal of an olive tree, without the fruit, these are your best options. Visit Bayscape Landscape’s planting page to learn ore about our planting services.
  • Second, let’s face the facts – timing is everything. In order for spraying to be effective, olive trees must be sprayed annually, in the first quarter of the year, and well before the flowers begin blooming in late spring and early summer. It’s sometimes necessary for trees to be sprayed more than once (and during extended bloom periods, two applications may be necessary). We advise to schedule your tree care experts for olive spray treatments in January.  At Arbortek Trees we have access to the most effective treatments, at the correct time of year (which is January for us in the San Jose or Bay Area, CA).

**If you intend to use your olives for making oils or table fruit, read this article from University of California (Cooperative Extension – Santa Rosa, CA) on “Controlling Olive Fruit Fly at Home” and learn about the various treatments available.

**For more information on the Olive Fruit Fly, we site “Olive Fly Control” from

**To schedule a olive oil treatment, call Arbortek Trees at 408-288-2942 or email us to schedule an appointment at

Growing Fruit Trees in San Jose