by Dianne Weyna

During the lockdown… is probably how many stories will start these days. With all that time on my hands I have done a few experiments of tropical plantings.  Like millions before me I started a couple avocados seeds. Years ago, my mother grew an avocado that had reached six feet, and because it was growing in her office it got lots of attention (fake flowers from coworkers would show up). She and her 6-foot avocado were featured in a public interest article in the newspaper.  Living in Colorado, we never even thought of it fruiting, just a pretty house plant.  Telling a friend this story, she told me her mother had an avocado tree she planted from a seed of a particularly tasty avocado, which also had good avocados (they lived in Southern California).  Seeing fruit as a possibility now, a really tasty avocado seed for planting made sense, which is how my 2 seeds got started.

It started out as a Hass, which makes up 95% of the commercial avocados are in California. The original Hass avocado was sold to an amateur nurseryman and professional mailman Rudolph Hass, who planned to graft it to a Fuerte avocado.  The graft didn't take and he was going to cut it down, but his children liked the avocados it produced.  Many others liked it too, and in 1935 he patented the plant, plant patent #139. The mother tree was In La Habra, California, dying of root rot in 2002 at the age of 76. Because avocados are heterozygotic, seeds have a high amount of genetic variety. Therefore, if you want to grow a Hass avocado you must buy the grafted seedling. If you want to see what happens, plant a seed. Warning, some of the seed grown avocados can be barren. 

The Hass avocado (Persian americano ‘Hass') is a type A avocado, meaning its flowers bloom as females in the morning and shed pollen as males in the afternoon.  There are also type B's, which are just the opposite. There are hundreds of varieties of avocados, mostly from Guatemala or Mexico, the Mexican being hardier, Hass is Guatemalan. I have had an avocado tree that is probably 5 or more years old, mostly ignored and left alone in a pot, even rarely watered. I am taking better care of it now and it looks good. I plan on planting this one in the ground next spring, in a fairly protected spot. I have two other smaller ones, the lock down avocados, which I will keep in pots for now. The zones best for growing avocados are 9-11, they are frost tender at 24-30 degrees F, and they can get sunburned. They also like water, 2 inches a week, but well drained soil. This is a long-term experiment so stay tuned.

Reference:  UC master gardeners Napa, Sunset Western Garden, ucavo.ucr.edu.

Napa Master Gardeners are available to answer garden questions by email: mastergardeners@countyofnapa.org. or phone at 707-253-4143.  Volunteers will get back to you after they research answers to your questions.

Visit our website: napamg.ucanr.edu to find answers to all of your horticultural questions.

Photo credits: (Seedling) Mark Hofstetter, CC BY-SA 3.0 <http://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons; Pixabay, free photo