Everybody wants to beat Hass. The world over, breeders are looking for that golden ticket: to create a new avocado variety that has a combination of characteristics superior to Hass. There are some contenders. Who will eventually knock King Hass from the throne?

This past week, I attended a webinar where those involved in the avocado breeding program at the University of California discussed varieties they’ve developed that have the potential to supplement or possibly supplant Hass. This program has already given us a few excellent new avocado varieties, from Gwen to Lamb to GEM. More are on the way.

Yet for the purposes of today’s post, what is obvious about these varieties is that most are essentially wannabe Hass. That is not degrading to the new varieties at all; that simply tells us how good Hass is, how high is the standard that Hass has set.

To this day, out of the avocado varieties that I grow in my yard, if I had to give up all but one, I’d keep my Hass. The tree and its fruit are not perfect, but overall they are so far unbeaten.

My goal for this profile is to tell you about the different qualities of the Hass variety of avocado tree and its fruit that combine to make it the standard, as well as add some historical context, so that ultimately you can decide if Hass is an avocado variety that you want to plant in your yard.

My Hass avocado tree at seven years old.

Hass tree

Hass avocado trees are vigorous. They’re not slow-growing, weeping runts, like the Holiday variety. My Hass and every other one I know grows both up and out, forming a nice crown of canopy. Compared to Fuerte, Hass grows more upward; compared to Bacon and Reed, Hass grows more outward. Compared to Lamb and GEM, Hass simply grows more.

I planted a Hass tree in my yard in 2013 from a five-gallon container, and it reached 15 feet tall in five years. Since then I’ve pruned it back yearly to maintain it at around that height. And my children enjoy climbing in the tree:

I know of commercial avocado growers who maintain Hass trees a bit shorter, and I know of many unpruned Hass trees that ultimately reach over 25 feet.

Hass fruit

You know Hass fruit. Do I even bother describing it? I do because you may have only had the hit-or-miss Hass avocados from various countries of origin found at a grocery store, and you may be interested in how Hass picked from a backyard tree compares.

Hass avocados are medium sized. They’re bigger than Stewart avocados but smaller than Nabals.

Hass among some other avocado varieties.

The skin is bumpy, and it is usually green while the fruit is on the tree. Once picked, the skin turns purplish black as it ripens. But if the fruit is left hanging on the tree late into maturity, the skin will turn black before it is even picked (though it will remain hard).

Hass avocado seeds are small but not tiny. There aren’t many varieties that I know that have reliably smaller seeds in proportion to their flesh: Pinkerton, Jan Boyce, Sharwil, and maybe Stewart. Many avocado varieties have larger seeds.

GEM and Hass avocados.

The coat on a Hass seed always remains adhered (it doesn’t stick to the flesh); I find this important because it takes an annoying extra few seconds to prepare an avocado for eating if the seedcoat is stuck to the flesh, as can happen with Fuerte, for example.

The flesh of a Hass avocado is a pleasing color of green with gold toward the center; it is never pale yellow like Zutano although it is also never quite as gold as Sharwil nor as green as Lamb.

I have never met anyone familiar with avocados who doesn’t like to eat Hass. Some aficionados rank other varieties above Hass in terms of taste, but Hass is never far behind. I’ve heard such people say their favorites to eat are Fuerte, or Jan Boyce, or Gwen, or Nabal, or Reed, but Hass is still always in their top handful. 

What you must know is that a Hass avocado picked from a backyard tree is different in many ways from a grocery store Hass. First, a backyard Hass ripens from green to purple-black, not the off colors of brown and orange that occur on a grocery store Hass. These unattractive colors are caused by refrigeration.

Hass on left just picked from tree . . . Hass on right ripe and ready to eat.

Next, there are almost never rots in the flesh of a backyard Hass nor are there any fibers. Almost every single avocado from a backyard Hass is perfect inside. And since you are in charge of when to harvest, the flavor is as you like it: mild in the early season (say, March in Southern California) or rich from mid season (usually starting in May).

A Hass picked from a backyard tree at the right time is so nutty rich that if you add it to a salad it stands out, and if you mash it into guacamole you might not even bother adding salt or salsa.

My video about the eating qualities of the Hass avocado.

Hass harvest season

I can pick good-tasting fruit from my Hass tree in March, but the remarkable thing about Hass is that the fruit will ripen and taste decent before it’s even really in season, in February, even January. Some other varieties won’t do this. If you pick a Gwen before June, its neck might shrivel even though its taste can be satisfactory.

Most people characterize Hass as a spring into summer fruit, so the harvest season for prime flavor down south runs roughly April through July; and then the harvest season in Ventura and Santa Barbara is a month or two later. I’ve eaten great tasting Hass from right near the beach in Carpinteria as late as November.

In San Luis Obispo County you must add yet another month or two. I ate some good-tasting Hass from Morro Bay this past November, but the fruit actually tasted just shy of peak, like my Hass do in about April. That would make their harvest season at least six months later than mine. (I’m in Ramona, San Diego County.)

In 1935, when Rudolph Gustav Hass applied for a patent on his new avocado variety, he described the fruit as maturing “during summer: namely, May to September.”

Hass variety history

Rudie, as he was known to friends, planted the Mother Hass tree between San Diego and Morro Bay at the southern edge of Los Angeles County in La Habra Heights. He had bought some avocado seeds from a nurseryman in nearby Whittier named A.R. Rideout, which Rudie planted on his two acres in the spring of 1926. The plan was to graft the trees to Fuerte, the most popular commercial variety at the time.

And the trees were grafted, but one never took to the grafting and was allowed to grow up as a seedling until it produced fruit of its own. The tree and the fruit showed so much promise that Mr. Hass registered it as a variety with the California Avocado Society in 1932, and then in 1935 it was granted patent number 139. Hass made a deal with another Whittier nurseryman, H.H. “Harry” Brokaw, whereby Brokaw would pay Hass for buds from the Mother Hass tree and graft them onto his own rootstocks to sell.

Hass strengths

Compared to other varieties back in the 1930s, Hass was an improvement in a number of categories. The fruit cropping was consistent compared to Fuerte. The fruit didn’t drop before it was mature as happened with the Spinks. The tree was vigorous compared to Murrieta Green. The skin of the fruit was thin and leathery compared to the thick, shell-like skin of Mayapan. The skin didn’t crack or split while the fruit was still on the tree as happened with Laurel.

Compared to varieties that are grown today, Hass still has a leg up in many of these same categories. Stewart fruit cracks while still on the tree, GEM has thick and less pliable skin, Holiday trees lack vigor, Lamb fruit drops before it’s mature.

Hass weaknesses

The Hass avocado tree and its fruit have no serious weaknesses; there are merely imperfections. The original flaw of Hass was the color of its peel. In 1945, Rudolph Hass’s neighbor in the Whittier area, Harlan Griswold, wrote an article for the California Avocado Society in which he promoted the new Hass variety in every way, except to acknowledge one handicap: “Its single disadvantage is its black color which has been associated in the minds of the public with poor quality fruits.”

Others echoed this observation. Writing from Israel, R.J. Ticho and B. Gefen said in 1965, “The Hass carries well to distant markets and tops even the Fuerte in quality, but its well known drawback is its black and warty surface.”

Fuerte was the main cause of the negative view of Hass’s peel color and texture. As the highest quality commercial avocado at the time, Fuerte had gotten everyone used to thinking the best avocados have smooth, green skin.

In fact, when Bob Bergh started breeding avocados at the University of California in the 1950s he was tasked with creating a sort of Fuerte-Hass hybrid. Growers wanted most of the attributes of Hass except for its peel color. Bergh came up with the Gwen variety, which when you look at it, appears like a Hass whose skin stays green.

Gwen avocado.

Everything is inverted now. We are used to quality avocados with black skin because of Hass, so much so that commercial farmers are extremely hesitant to plant any new varieties that don’t have black skin.

A weakness of Hass that remains a weakness today is its susceptibility to tip burn on the leaves during the fall and winter because of the tree’s sensitivity to salt and drought. Some other varieties are less sensitive in this way.

Tip burn on leaves of Hass avocado tree in winter.

Hass could also be tougher when faced with extreme heat. My Hass dropped all of its young fruit in the July 2018 record heat (about 118 degrees) whereas my nearby Reed and Lamb at least held onto a few pieces of new fruit. This topic of the heat tolerance of avocado varieties hasn’t been formally studied in California to my knowledge, but I’ve been told by others that they’ve also observed Reed, Lamb, Pinkerton, and GEM faring slightly better than Hass in extreme heat.

(See my soon-to-be-updated post, “Heat tolerance of avocado varieties.”)

And Hass isn’t as cold hardy as some other good avocado varieties, such as Fuerte, although it’s also not much weaker. My yard dropped to 25 degrees on February 5, 2020, and the foliage of my Hass was slightly more damaged than my Fuerte. However, the Hass held onto all of its fruit whereas the nearby Reed and Lamb trees dropped numerous avocados. That could have been because they were carrying heavier crops than the Hass; I’ve heard others observe that Lamb tolerates cold slightly better than Hass. Unfortunately, again, I know of no formal studies comparing the cold tolerance of Hass to the newer varieties that are common today.

Hass bearing habit

The original Hass seed is thought to have possibly come from a fruit of the Lyon variety. Lyon trees were known to fruit so heavily and early in their lives that they could stunt or even kill themselves. Whether or not Hass came from Lyon, Hass did inherit a habit of fruiting fairly young and consistently.

Something growers immediately appreciated about Hass compared to Fuerte was this early and consistent fruit production. But how does the yield of a Hass tree compare to newer varieties?

In a study done on trees in Irvine between 1999 and 2005, GEM and Lamb both produced about the same amount, both being more than Hass. However, in an ongoing study of different avocado varieties in Ventura County, it was found that between planting in 2012 through the 2019 harvest, Hass and GEM trees yielded about the same amount of fruit as measured in terms of weight, both of these yielding more than the other varieties (Reed, Lamb, and Carmen).

An interesting note from the Ventura study is that the canopy size of the Hass trees was bigger than that of GEM. Because of this, one conclusion has been to describe GEM as “more efficient” than Hass.

Seven-year-old GEM avocado tree; compare to my much larger seven-year-old Hass above.

In my own yard, I grow all of these varieties. My Carmen and GEM trees are not the same age as my Lamb, Reed, and Hass. But these latter three are all seven years old now and I keep track of their production. My Lamb has produced well, but it has produced the least of the three, mostly due to its alternate bearing habit. Reed production has been excellent and consistent, but still less than Hass. My Hass has yielded the most, and it also has the largest canopy among the three trees.

Bottom line: Hass may not be the top producer, but it remains among the best-producing avocado varieties.

Is a Hass avocado tree right for your yard?

One situation in which I can imagine a Hass avocado tree not suiting a yard is where the allotted space is small. If you don’t want to prune the tree, then you need around 25 feet in all directions for a mature Hass. 

But avocado trees are easy to prune. Their wood is soft and their leaves are too. So that’s an option.

Hass avocado trees in Ventura County planted 12 feet apart and kept pruned down to 10 feet tall.

I can understand not wanting that chore to deal with though, in which case a naturally smaller variety such as GEM or Lamb, or even Reed or Pinkerton would fit better.

Another situation where Hass wouldn’t be the right choice is if you have access to good Hass fruit already. Maybe a neighbor has a tree or you have a place to buy Hass avocados of reliable quality. In that case, I’d plant an avocado tree with a harvest season that is complementary to Hass. Good options for earlier avocados include Fuerte, Bacon, Sharwil, Sir-Prize, and Pinkerton. Good options for later avocados include Reed and Lamb.

My video profile of the Hass avocado tree.

The Mother Hass avocado tree in La Habra Heights declined in health and was eventually cut down in 2002. You can still see the plaque commemorating the tree in the front yard of a house that was built long after the original Hass seed was planted in 1926. I’ve driven by and even snapped a couple blurry photos.

Plaque in lawn in center of photo shows location of original Hass avocado tree.

I’ve also purchased a slice of the Mother Hass tree, which sits on my bookshelf. The wood from the felled tree was donated to the California Avocado Society, who has made some beautiful products with it.

My slice of a branch of the Mother Hass avocado tree.

You too can own a piece of avocado history through the California Avocado Society.

Or you might choose to just consider next time you’re eating a Hass avocado how awesome it is that branches taken from this one chance seedling tree planted in 1926 in Southern California have been used to create millions of Hass avocado trees all over the world. After 94 years, the best efforts of breeders have yet to conquer Rudie Hass’s luck.

A page with links to my avocado variety profiles is HERE

A page with links to all Yard Posts is HERE

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