{"id":14449,"date":"2022-03-25T14:07:58","date_gmt":"2022-03-25T21:07:58","guid":{"rendered":"https:\/\/gregalder.com\/yardposts\/?p=14449"},"modified":"2022-03-25T14:07:58","modified_gmt":"2022-03-25T21:07:58","slug":"pinkerton-avocado-tree-a-profile","status":"publish","type":"post","link":"https:\/\/gregalder.com\/yardposts\/pinkerton-avocado-tree-a-profile\/","title":{"rendered":"Pinkerton avocado tree: a profile"},"content":{"rendered":"\n

No less an authority on avocado varieties than Oliver Atkins wrote in 1978<\/a> that Pinkerton \u201cappears to be the best variety we have come up with for California since the Hass.\u201d Why then, over the ensuing 44 years, have most of us in California never eaten a Pinkerton avocado?<\/p>\n\n\n\n

While I don\u2019t have a precise answer, this post will touch on some reasons as I aim to answer another, more important, question: Is Pinkerton a good avocado variety to plant in your yard?<\/p>\n\n\n\n

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Fruit characteristics<\/strong><\/p>\n\n\n\n

First let\u2019s look at the fruit. Pinkertons are \u201cnecky.\u201d In other words, they have an elongated pear shape rather than a round or egg shape. And in some years in some locations, Pinkerton avocados can look extremely stretched out.<\/p>\n\n\n\n

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Necky Pinkerton.<\/figcaption><\/figure><\/div>\n\n\n\n

Fortunately, the flesh inside a Pinkerton\u2019s neck is solid. This is unlike the Don Gillogly variety<\/a>, for example, which has a seed cavity inside extending up its neck.<\/p>\n\n\n\n

Pinkertons are larger than Hass, but more than that they have a very small seed, meaning you get more flesh to eat in any given avocado.<\/p>\n\n\n\n

The flesh has a fine texture and no fibers to speak of. It has a pleasant yellow to green color, and the taste is mildly nutty, very pleasing.<\/p>\n\n\n\n

The skin of Pinkerton is a similar green to an unripe Hass and is about as bumpy as Hass, but the Pinkerton\u2019s bumps are sharper. As a Pinkerton avocado ripens, its skin remains green. The skin is a bit thinner than that of Hass.<\/p>\n\n\n\n

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Normal Pinkerton.<\/figcaption><\/figure><\/div>\n\n\n\n

The skin peels off the flesh of a Pinkerton acceptably sometimes but not always.<\/p>\n\n\n\n

Occasionally, a Pinkerton avocado develops a black spot near its bottom end, and this deterioration affects the flesh inside in that area. It\u2019s not as common an occurrence as on some varieties such as Bacon, however.<\/p>\n\n\n\n

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Bottom rot on Pinkerton.<\/figcaption><\/figure><\/div>\n\n\n\n

The main peculiarity of Pinkerton is that it takes two to three weeks for the avocado to ripen from the time it is harvested. This can test one\u2019s patience. Moreover, it can be tricky to judge when a Pinkerton avocado is fully ripe since it softens in the neck before the base. You have to wait to cut it open only when both the neck and base feel ripened.<\/p>\n\n\n\n

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Variety history<\/strong><\/p>\n\n\n\n

Pinkerton\u2019s long ripening time was thought to be of benefit when the variety began being test-grown by farmers because it would allow them to ship the fruit long distances.<\/p>\n\n\n\n

According to accounts in the California Avocado Society Yearbook of 1978, the variety was discovered by John Pinkerton, who found the seedling growing among Hass, Edranol, Corona, and Rincon trees on his ranch in Saticoy, Ventura County, in the early 1960s. The seedling bore consistent crops of high quality fruit so he grafted wood from it onto three older trees near his office, where he could watch them. He evaluated these trees for a number of years until he was convinced that the variety had commercial potential. In 1975, he received a plant patent on the Pinkerton avocado. Sadly, only three years later, John Pinkerton passed away.<\/p>\n\n\n\n

One hope for Pinkerton was that it would, as Oliver Atkins put it, \u201chelp fill the void caused by the declining Fuerte acreage and, as it ripens and sizes ahead of the Hass, should tend to stop growers from picking Hass too early.\u201d (CAS Yearbook, 1981)<\/p>\n\n\n\n

In 1982, Brokaw Nursery (also located in Saticoy) ran this advertisement for Pinkerton in that year’s California Avocado Society Yearbook:<\/p>\n\n\n\n

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Note that the ad calls Pinkerton a “winter” fruit.<\/figcaption><\/figure><\/div>\n\n\n\n

Frank Koch, writing in his 1983 book Avocado Grower\u2019s Handbook<\/em>, quoted one of Pinkerton\u2019s early supporters (Warren Currier) as pointing out that Pinkerton trees seem to have \u201cmuch greater limb strength and tolerate winds better than most other varieties.\u201d This has proven true over the decades. On the other hand, Currier claimed that Pinkerton was less alternate bearing than Hass, which has not proven true in my experience. All of the mature Pinkerton trees that I know have clear \u201con\u201d years and \u201coff\u201d years.<\/p>\n\n\n\n

By 1984, weaknesses of Pinkerton, especially from the perspective of a commercial grower, had become obvious. Bob Bergh, director of the avocado breeding program at University of California, Riverside, listed these imperfections in an all-around fascinating article in the California Avocado Society Yearbook called \u201cAvocado Varieties for California.\u201d<\/a> They included the fact that Pinkerton trees fluctuated in their production just like Hass as they got older. Also, Pinkerton had a \u201cshorter harvest season than Fuerte;\u201d the Pinkerton fruit \u201csometimes have hard-spot ripening problems;\u201d and some fruits \u201ctend to become too large\u201d and have \u201ctoo pronounced neck development.\u201d<\/p>\n\n\n\n

In 1989, Hank Brokaw (of Brokaw Nursery) wrote<\/a> about the challenges of introducing the new Pinkerton variety. Brokaw had planted a few thousand acres of Pinkertons, but found that the slow-ripening of Pinkertons was now seen as a disadvantage since retailers wanted fast turnover, and handlers (companies who buy avocados from farmers and sell to distributors and retailers) complained that Pinkertons “couldn’t be stored under refrigeration.”<\/p>\n\n\n\n

As a commercial variety, Pinkerton did not fit into the new marketing and supply chain trends of that era, and not long after, most farmers in California gave up on the variety.<\/p>\n\n\n\n

Home growers continue to plant it though, in part because the tree is slightly smaller than Hass and many other varieties.<\/p>\n\n\n\n

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Tree characteristics and bearing habit<\/strong><\/p>\n\n\n\n

Pinkerton avocado trees end up shaped much like an orange tree, with a domey, spreading form. And they take this shape for similar reasons to an orange. In one year, branches will grow upright, and then flower.<\/p>\n\n\n\n

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Pinkerton tree with heavy bloom after a summer growing upright branches.<\/figcaption><\/figure><\/div>\n\n\n\n

Then the tree sets lots of fruit, and the weight of the fruit bends the branches down.<\/p>\n\n\n\n

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Same Pinkerton tree bent double while carrying a heavy load of fruit.<\/figcaption><\/figure><\/div>\n\n\n\n

The next year all of that fruit is harvested, the tree grows more upright branches, then blooms heavily the following spring and the process repeats.<\/p>\n\n\n\n

The leaves of Pinkertons often have margins that undulate.<\/p>\n\n\n\n

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Pinkerton avocado leaves.<\/figcaption><\/figure><\/div>\n\n\n\n

The flowers of Pinkerton behave in the \u201cA\u201d fashion.<\/p>\n\n\n\n

Pinkertons tend to set much of their fruit in clusters rather than being distributed evenly throughout the canopy. They set fruit in clusters especially during years when they have few fruit on the tree overall.<\/p>\n\n\n\n

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Clusters of fruit on a Pinkerton tree during an “off” year.<\/figcaption><\/figure><\/div>\n\n\n\n

This is similar to some other varieties, such as Gwen. However, unlike Gwen, once new fruit has set on Pinkerton most of it holds all the way until maturity.<\/p>\n\n\n\n

Pinkerton starts fruiting at a young age, too. The first Pinkerton tree I ever planted was in a five-gallon container and already holding a nice sized avocado. Here\u2019s one in a three-gallon sleeve holding two young fruit:<\/p>\n\n\n\n

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Pinkerton\u2019s precocity has been used by breeders such as Bob Bergh, who wrote<\/a>: \u201cSeedlings [start bearing] in maybe the fifth or sixth year and more in the eighth and ninth year . . . Seedlings of ‘Pinkerton’ have the remarkable ability to start bearing the second year from planting.\u201d<\/p>\n\n\n\n

In addition to bearing fruit at a young age, Pinkerton out yields many varieties overall. An avocado farmer in South Africa, where Pinkertons are a more common commercial variety than here in California, once told me that Pinkertons were by far his most productive variety.<\/p>\n\n\n\n

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Production on a six-year old Pinkerton tree in Poway, San Diego County.<\/figcaption><\/figure><\/div>\n\n\n\n
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In need of a pollenizer<\/strong><\/p>\n\n\n\n

Pinkerton\u2019s high productivity only comes when another kind of avocado tree is growing nearby though, in my experience and in the experience of others (see Gad Ish-Am\u2019s comments here<\/a>).<\/p>\n\n\n\n

I planted a Pinkerton tree in 2016 that bore a few fruit each year until the spring of 2021 when an Edranol I planted beside it first bloomed. The Pinkerton had few flowers itself that spring but still yielded 29 avocados from its six-foot diameter canopy. (It had only yielded six avocados in the previous five years combined, when it had no pollenizer nearby.)<\/p>\n\n\n\n

Which varieties pollenize Pinkerton well? Other than Edranol, I\u2019ve personally seen evidence that Fuerte, Bacon, and Sir-Prize work. I\u2019ve also read that Ettinger does (see \u201cThe Israeli Ways<\/a>\u201d).<\/p>\n\n\n\n

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Cold and heat tolerance<\/strong><\/p>\n\n\n\n

Unfortunately, I have grown Pinkerton for nine years in a location that often gets too cold and too hot for avocados generally. Fortunately, this has given me a chance to observe firsthand the variety\u2019s limits.<\/p>\n\n\n\n

As for cold tolerance, Pinkerton is roughly equal to Hass. It is not a variety that tolerates cold better than others that we commonly grow in California.<\/p>\n\n\n\n

As for heat tolerance, Pinkerton leaves and limbs get sunburned in high heat more than many other varieties, but this is partly because they often carry heavy loads of fruit that expose the canopy to the sun. In this way, Pinkerton is weak in the heat. However, Pinkerton is strong in the heat in that it does not drop its fruit as much as other varieties. (See details in my post, \u201cHeat tolerance of avocado varieties.\u201d<\/a>)<\/p>\n\n\n\n

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Harvest season<\/strong><\/p>\n\n\n\n

The main harvest season for Pinkerton starts in March. I\u2019ve picked them in January and February, when they can ripen and taste acceptable, but only in March do they start to reach their potential.\u00a0<\/p>\n\n\n\n

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Mature Pinkertons in March.<\/figcaption><\/figure><\/div>\n\n\n\n

Though commercial growers of yesteryear tried to market Pinkerton as a winter fruit, the main crop of Pinkerton is rightly considered a late winter \/ early spring avocado. In fact, in the 1989 article by Hank Brokaw<\/a> mentioned earlier, Brokaw says that John Pinkerton’s ranch foreman originally told him that the Pinkerton avocado “matured about April.” Growers were just trying to market Pinkertons earlier in order to avoid competing with Hass, which also matures about April.<\/p>\n\n\n\n

That being said, Pinkerton blooms earlier than many varieties (including Hass), and in some locations it will start flowering as early as October. Any fruit that sets there in the fall will ripen beginning around the following fall. But even with Pinkerton\u2019s early bloom, it still tends to actually set most of its fruit during the later months of bloom (March, April, even May).<\/p>\n\n\n\n

I\u2019ve eaten Pinkerton as late as July, but I\u2019d say that high quality Pinkerton fruit from a tree in Southern California is not likely to be picked past May or maybe into June.<\/p>\n\n\n\n

In this video I profile the Pinkerton avocado using a late-season fruit:<\/p>\n\n\n\n