Over the last hundred years or so, the price of avocadoes has not changed.  Back in 1920, the price of avocadoes, which were a newly introduced delicacy in California, was around $1 a piece and, today, the price remains about the same.  Of couse, a dollar in 1920 could buy a lot more than a dollar today and avocadoes at that time were luxury items.  In fact, when avocadoes were first grown in California, the only buyers were high end restaurants.  If you were not well-heeled, you probably did not even know what an avocado looked like since avocadoes were      not commonly found among grocery produce.

The history of California avocado production begins in Mexico.  In 1911, a nurseryman in Altadena enlisted the assistance of a Mexico City resident in searching out desirable avocado varieties.  Soon, budwood (bud-bearing shoots or young stems) of different trees were being shipped, including variety number 15, discovered in a backyard in Atlixco, a town 120 miles southeast of Mexico City.  Buds of the various Mexican varieties were grafted into small avocado seedlings in Altadena.

Two years later, in 1913, there was an unprecedented freeze in Southern California.  Orange groves were decimated and all the avocado seedlings growing in the Altadena nursery froze — except for variety number 15.  Because of its ability to survive the freeze, this variety became known as ‘Fuerte,’ which means strong in Spanish.

The summer before the freeze, a certain John Wedon, who had just acquired land in Yorba Linda, pre-paid the Altadena nurseryman for 40 avocado trees of familiar varieties that were to be planted on his property.  When he came to the nursery to pick up his trees following the freeze, he was informed that the trees he had ordered were dead.  Mr. Whedon wanted his money back but the nursery owner said that was impossible since he had lost everything in the freeze.  The nurseryman offered Mr. Whedon 40 Fuerte trees instead and, with great reluctance but having little choice in the matter, Mr. Whedon took the unfamiliar trees.  Thus, the first avocado grove in California was planted.  Mr. Whedon’s disappointment soon disappeared when his trees began producing gorgeous green fruit.  And then, in 1922, there was another major freeze and, once again, nearly every avocado tree for miles around, with the exception of Whedon’s ‘Fuerte’ specimens, was killed.

I was prompted to investigate the ‘Fuerte’ avocado‘s origins upon receiving the following email from Marilyn Blanck:

“I have an enormous ‘Fuerte’ avocado tree in my backyard in northeast Alhambra that produced around 800 avocadoes over the past year.  Many of my neighbors have them, too. My house was built in 1938 and the tree was not there then. But it appeared around 1940 and is still going strong at 75 years old.  I moved here in 1962 and the tree was already very, very large. I’ve been having it pruned every two years since then.  I do not give it special irrigation or food.  The tree’s roots extend out into my backyard, and the backyards of two neighbors. The roots get water when we all water our lawns, which is once a week or so. The only time the soil around the trunk gets any water is when it rains.  The tree is located over the lowest part of the property, which means run-off water, little though there is, goes under the deck to the base of the tree.

“When we moved into the house, this tree had a big growth of ivy underneath that harbored families of rats. After a few years of putting up with this mess, we had a large deck built around the tree. That was some time in the 70s, and everything’s been fine since, and the rats seem to have been been replaced by a cute family of squirrels that enjoys running and leaping around in the tree. This deck covers approximately 1/4 of the backyard. There is no leaf mulch under my tree; does a wooden deck count as mulch?”

Ms. Blanck’s avocado tree is an example of horticulture being more of an art than a science.  The history or her avocado tree demonstrates that accepted horticultural wisdom may frequently be contradicted by actual experience.  Still, her experience does illustrate some important horticultural principles.

Any arborist will tell you in no uncertain terms to never build a deck around a tree because of potential problems with standing water under the deck.  Yet it was precisely the construction of a deck that solved Blanck’s rat problem and, as she suggests, may have contributed to the water economy of her tree by acting as a kind of mulch.  The deck would probably have diminished evaporation of water from the soil surface or, at a minimum, helped to keep her avocado roots cool and unstressed.  In order for this to occur, however, her soil would have to have excellent natural drainage; otherwise, the water would puddle there and bring on avocado root rot.   The fact that the soil around the trunk of her tree is nearly always dry is not an issue since it is a tree’s peripheral roots — those directly under the edge of a tree’s canopy or leaf cover — that absorb most of the water that a tree requires.

I find it interesting that a family of squirrels lives in Blanck’s tree and she still harvests hundreds of fruit.  Since she and her neighbors have heavily producing avocado trees, perhaps there is enough fruit to go around for both squirrels and people. It’s kind of like what they say about planting lettuce around a garden in order to keep out rabbits.  From what I hear, the rabbits will satisfy themselves by munching the lettuce and thus leave the actual garden alone.

Tip of the Week:  “In the same area as the avocado tree,” Blanck wrote, “I have three old camellia bushes back in a corner. They get about as much water as the tree, and they look healthy, too. I never feed them but their dead leaves and other leaves dumped in the area might act as a little mulch. You could call this good luck, I guess — or is it, by accident, a perfect environment for both the avocado tree and the camellias?”  It is widely acknowledged that ‘Fuerte’ avocado is one of the easiest fruit trees to grow and Japanese camellia (Camellia japonica) is one of the easiest flowering shrubs to grow when it comes to urban environments in Southern California.  Both are suprisingly cold tolerant and, when mature, water thrifty.  If you are wondering whether you can grow them in your area, look for California laurel sumac (Malosma laurina) in the surrounding native landscape, since wherever laurel sumac grows, avocado and camellia will grow, too, as long as the camellia is protected from hot sun.