Question:

Will olive trees grow in New Mexico?

- Jeannie O., Truth or Consequences, NM

Answer:

I have also wondered why olives aren’t grown in New Mexico, especially when visiting northern parts of the state, where the vistas look so much like Andalucia, Spain, with rolling hills dotted by olive trees.

Let us quickly clarify so that we aren’t confusing the tree species that produces table olives, Olea europaea, with our native New Mexico olive trees, Forestiera neomexicana, also known as New Mexico privet or desert olive. Forestiera neomexicana, grown as a shrub, tree, or even hedge, is an excellent landscape plant for most of New Mexico. Although from a different genus and species, both Forestiera neomexicana and Olea europaea are in the Oleaceae plant family. Other plants in this family include lilac, jasmine, and forsythia. The dreaded Elaeagnus angustifolia, also known as Russian olive, is from a different plant family and is an invasive weed all over the western United States.

The rest of the column is just about Olea europaea. Currently, all commercial olive production in the United States is in California, except for a few acres near Phoenix. Olives are native to the Mediterranean and parts of Asia and Africa. Some sources list Olea europaea as being cold hardy to USDA growing zone 7. In New Mexico that would include Albuquerque and, basically, any place warmer. However, other sources list Olea europaea as being cold hardy to USDA zones 9 or 10, meaning they may not last through cold winters in any part of our state. 

For an interactive map of the USDA cold hardiness zones, go to http://planthardiness.ars.usda.gov/ and type in your zip code. There are some ways to slightly adjust the growing zone in your yard. Within a landscape, strategically placed microclimates can increase the planting zone by a half point, like on the west side of a stone wall. Similarly, the shaded north side of a house can be a half zone colder than the surrounding area.

As far as growing olives in New Mexico, it all comes down to what you want to do with your trees. Olives take 5-6 years to mature enough to set fruit and more to get an actual crop. In New Mexico, that means several winters of gambling with the cold before even a chance of flowering/fruiting. This is why they are not normally recommended for commercial production in New Mexico.  The risk of plant death is high, and the risk of no yield is even higher, depending on where you are in New Mexico.

I checked in with Dr. Richard Heerema, NMSU Extension Pecan and Pistachio Specialist, to get his recommendation. Heerema says, “In backyard orchards in the warmest parts of New Mexico, Olea europaea can grow and produce well. If someone wants to plant in Albuquerque or Truth or Consequences, they should pick a warm, sheltered area and understand that getting a reliable crop will be difficult, even if the tree itself lives through winter. Also, the cultivars available to us in the United States are those better acclimated to southern Europe, but there are native varieties that grow as far north as Russia, so those are likely to produce more reliably in colder parts of New Mexico.”

When you are ready, the University of California Division of Agriculture and Natural Resources published helpful guides on growing, harvesting, and pickling olives. Fun fact: olives are different in color because of their ripeness at harvest time, much like our beloved chiles.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.

Links:

For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms and the NMSU Horticulture Publications page.

Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at desertblooms@nmsu.edu, or at the Desert Blooms Facebook page.

Please copy your County Extension Agent and indicate your county of residence when you submit your question!