Las Vegas Sun

March 19, 2024

5-MINUTE EXPERT:

Extending a branch to a much-maligned Las Vegas Valley staple

olive branch

Shutterstock.com

Grandfathered in

The Clark County ban on olive trees only applied to the planting of new ones. Existing trees are not required to be removed, so there are still hundreds of trees still in the valley.

Tip

If olives have a round, beige-ish scar on them, you might want to throw them away. They may have been visited by the olive fly, whose larvae burrow into the fruit.

Did you know?

There aren’t different trees for green and black olives. And black olives didn’t start out black — they are olives that were picked while green and subjected to a preserving process that involves an alkaline solution and an iron compound. Fruits start out green and turn a purplish-black color when ripened. They contain the same pigment that causes Concorde grapes to turn dark purple.

It doesn’t need much water, offers an abundance of shade and boasts two-toned leaves that create a shimmering effect when blown by the breeze on a sunny day.

No wonder that when Las Vegas homeowners discovered decades ago that the olive tree was a great fit for the city’s arid environment, they went wild over the plant.

The problem was, they went a little too wild. They sort of became Johnny Oliveseeds, planting so many of the trees that the pollen from them became a public health hazard.

And that’s why today, it’s unlawful to grow flowering olive trees in Clark County. Officials banned them in 1991 with an ordinance that stated, in essence, types that produce olives couldn’t be planted and types that do not produce olives could.

Since then, the olive tree’s approval ratings are about equivalent to those of Congress, especially among people who are allergic to the pollen.

But that’s completely unfair, arborists say.

“Olive trees are beautiful trees,” said M.L. Robinson, a professor and horticulture specialist at the University of Nevada Cooperative Extension. “I wish I could promote them here, because there’s a possibility we could produce olives here as a Southern Nevada crop. But people get excited, and they want to ban something. ‘My kid’s sneezing, let’s ban olive trees.’ ”

Peel away the image problem, Robinson and others say, and there’s a wonderful plant underneath.

Did you know?

There are olive trees in the Middle East that have been alive for more than 1,000 years.

What’s the deal with the pollen?

The olive tree’s pollen isn’t any more potent for allergy sufferers than other types of pollen. It’s just that there are so many olive trees in the valley that their pollen is more highly concentrated than that of other plants. (An exception is the mulberry tree, which also was overplanted.)

Most pollen falls within a few yards of the tree, but highly concentrated amounts of it can be blown around and cause problems.

Allergy sufferers who have olive trees in their yard can get some relief by hosing down the trees in the morning, knocking the pollen off of the flowers and helping prevent it from becoming wind-borne.

Pruning

Untrimmed, an olive tree has a bushy canopy. But a fairly common practice in Las Vegas, especially on the Strip, is to trim olive trees in a topiary style, resulting in what look like balls of leaves at the end of branches. It looks cool, but experts say it stresses the trees. The fewer the leaves, the less the tree is able to photosynthesize and create the sugars it needs to grow.

Caring for olive trees

Olive trees can be messy, dropping leaves and mass quantities of fruit. Shirl McMayon, president of the Southern Nevada Arborists Group and account manager for GTI Landscaping, says homeowners should water the trees just enough to keep them alive, which limits growth.

• Follow the Southern Nevada Water Authority’s watering restrictions. Examine leaves periodically and up the water if they start to become flaccid.

• Fruit-producing trees can be sprayed with a chemical that keeps them from flowering, which in turn prevents them from producing fruit. It can cost $15 to $40, depending on the tree’s size. “The drawbacks? It’s a chemical, so you’re putting something out there that’s not natural. You’re knocking flowers off of a tree, which the bees don’t like. And some can drop on plants underneath, so those are going to slow down, as well.”

• It’s common for property owners to trim back or remove trees that hang over sidewalks or driveways. Why? Because when fallen olives are stepped on or run over, their pigment leaves stains on concrete.

• Another word of caution: If an olive tree is being grown in a patch of grass or has a garden around the trunk, putting fertilizer on the turf or plants will cause the tree to produce more leaves and olives.

Harvesting olives

Olives generally start sprouting in autumn. A common method for harvesting them is to lay sheets or tarps around the tree, then use a pole to shake or hit the branches, jarring them loose.

Some types of olives

1. Kalamata: Almond-shaped, deep purple, preserved in red wine vinegar and/or olive oil. Smoky, fruity flavor.

2. Castelvetrano: Bright green and roundish with meaty flesh and a mild, sweet flavor.

3. Manzanilla: Standard green olive.

4. Mission: Standard black olive.

5. Beldi: Moroccan export. Dry-cured, wrinkly, intensely flavorful.

6. Picholine: Crisp and crunchy, with a tart and nutty flavor. From France.

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