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Arizona Olive Trees: Life Will Find a Way

Reproduction is one of the most powerful forces in nature.

In the plant world, this power is on grand display every spring in the form of fantastic flowers and although flowers look and smell nice,  it’s all business for the plant. When plants require the services of insects such as bees to deliver pollen from one plant to another, those services are advertised and paid for in the currency of attractive flowers and sweets (nectar).   This is an efficient system with little wasted pollen.

Other plants are not so economic and literally toss their goods to the wind, producing a dust storm of pollen in hopes that out of the enormous quantity of pollen produced, some will reach their mark.

Wind Pollinated Problems

This is where we come in.    All this blowing pollen gets on our skin, in our eyes, up our noses, and down our windpipes, causing itching, sneezing, dripping, and wheezing.

The Arizona Olive Tree: Public Enemy Number One

A popular imported landscape addition since around the 1930s, the Olive tree has become one of Arizona’s’ most notorious contributors to our seasonal allergy misery. The Olive tree is so sensitizing that planting fruiting Olives has been discouraged or banned in Phoenix and Tucson since the 1960s    Nurseries and landscape companies are not allowed to sell or plant them.

And yet, the Olive tree is an attractive tree and still very popular, and so to get around the planting restriction, “non-fruiting” (less pollen and less fruit) varieties, such as the San Hill Olive, were developed and sold by nurseries as a less messy and hypoallergenic alternative.

If you wanted a nice, hypoallergenic shade tree in your yard in Ahwatukee you just asked your landscaper or nursery for a Swan Hill Olive and you were set.

Perhaps not.

Ahwatukee Olive Trouble

One problem is that there have been reports of nurseries in the East Valley selling conventional Olive trees as the non-fruiting variety.  You probable could not tell the difference in a newly planted tree and by the time it became clear that your supposedly impotent hypoallergenic purchase was actually quite capable of doing it’s part to propagate the species, yanking a mature tree out of the yard might not be an appealing option.

The other problem (which is what made me think of that phrase from Jurassic Park) is that non-fruiting Olive trees may revert back to their natural, virile state.   This was described to me by a landscape business owner in Ahwatukee who has witnessed this transformation in trees that he knew to be true San Hill varieties, but which, in time, found their true, pollinating machismo, as it were.

Mother nature is not easily fooled.

Swan Hill Olive Tree With Suspicious Pollen Clusters