Photo by Hannah Rose

An avocado is as common as the banana in our fruit bowl. Name five tropical fruits and avocado is sure to be on that list. Or, has it become so common that we don’t even consider it tropical therefore exotic? Lately, I have been obsessed with avocados. I can’t seem to get them out of my head. I want to know more about this most common fruit.

We have 86 avocados trees at Kumu Aina, of 25 varieties. (Grocery stores carry only one or two varieties: Haas and Sharwil.) I have a lot to learn about where they come from, what they taste like, when they ripen, how to propagate more, and who pollinates them. I do not attempt to answer all these questions today. However, I do consider it a challenge to find them.

In our transient society we may have inherited an avocado tree or two, or, like me, a whole orchard of them, not knowing the varieties of many of them.  We may have thrown out some seeds, planted a few grafted trees that we were told were good or would fruit at a given time. For almost eight years, I have been listening to avocado eaters and they want these things out of their fruit: creamy or buttery, not stringy, not watery, good flavor, big in size, small in seed, year-round production, and predictable ripening. I think one knows what one wants from an avocado but the trick is getting it.

Photo by Hannah Rose

One might consider that there are five species or races of avocado [technically there are three…two (Guatemalan and West Indian ) being an expression of one botanical species Persea Americana and one distinct species (Mexican) Persea Drymifolia]. Of the five, let’s consider them to be Guatemalan, West Indian, Mexican, Seedling and Hybrid.

Guatemalan: Blooming in late spring, this species will produce fruit in winter to spring (November to May). You can expect fruit in 3 – 4 years but maybe as long as 6 – 7. The skin tends to be thick or 1/16″ to 1/4″ thick, woody in texture, harder or coarsely granular with a rougher texture towards the stem. Leaves are deeper colored with new growth deeper bronze red. The seed fills the cavity and does not rattle when shaken. Fruit are borne on long stems, the skin is light green to purplish black and the meat is fiberless. Introduced to Hawai’i in 1885 it grows best in tropical highlands. Known varieties include Linda, Nishikawa, and Ohata. In my opinion, possible hybrids that resemble this species are Kahalu’u (an alternate year bearer), Marashige (an alternate bearer), Semil 34, and Green Gold.

West Indian: Blooming in early spring, fruits can be expected in summer to late fall (July to November)–usually not a winter avocado. Expect fruit from 5 – 6 years. Skin is more than 1/16″ thick and leathery in texture but smooth from yellow-green to maroon in color. It is the predominate race of avocado but does not grow well in California. This tree does best in tropical lowlands and they have the greatest tolerance to salinity. The seed is large and often loose in the cavity with two layers of seed coat. This may have been the race that was first introduced to Hawai’i in 1825. Known varieties include Ota. Avocados in my orchard that are similar include Greenwell, Malama, Keona, and Cliff.

Mexican: This race is identified most easily by the anise-like scent of its leaves and by its small fruit. It is considered the hardiest and most cold tolerant of all. Flowers appear in early winter and early spring with the fruit ripening in summer and fall. Also, it is small leaved and small fruited. The seed is large as compared to the fruit, which tends to be small. The skin is thin and typically glossy. Thin skin is easily pierced by fruit flies. Fruit can be produced in as little as 2 – 3 years. I don’t know of any cultivars but hybrids that resemble this race the most are Hass, Sharwil, Cliff, Green Gold and Fuerte. The hybrid San Miguel also has some of the characteristics.

Seedlings: Avocados are not true to seed, so that every seedling can be considered a variety. In essence you could have the best fruit from your seedling, continue to clone and give your friends grafted trees of your variety and make up a name like “Super Big, Buttery, Itty Bitty Seed that Ripens on Tuesday at 4:00 p.m.” cultivar. Seedlings (somewhat typical of seedlings in general) tend to be large trees, more vigorous and bearing fruit much later than grafted. Also, seedlings tend to produce crops in alternate years. It is worthy to note that unfavorable conditions or over-production can also lead to alternate year crops in any race or variety.

Hybrids: These are usually planned offspring resulting from cross-breeding of different avocados. These trees tend to fall in and out of favor. Hybrids that were popular 10 years ago may not be found at your favorite nursery today. Some may not even exist anymore. Nurseries, botanists, commercial growers, backyard hobbyist, and perhaps consumer demand, decide which trees to clone and which to let go by the wayside. Fuerte, a popular California avocado, is one of the oldest cultivars still of commercial importance. Hybrids were once mainly crosses between Mexican and either Guatemalan or West Indian. But today, I believe, you can find crosses of crosses. For instance, in the Green Gold, a Mexican/Guatemalan cross is crossed with a Sharwil (also a hybrid). Hybrids include: Nishikawa, San Miguel, Green Gold, Kahalu’u, Beardslee, and Sharwil.

Another thing to consider if you want to plant an avocado is whether it will be pollinated from other avocado trees in your yard or your neighbor’s yard. This is a little technical and I will try and explain it right. Flowers on avocado trees are hermaphroditic which means that their flowers contain both female (ovaries) and male (pollen) parts. They don’t produce these female and male flowers at the same time. The flower open as female and later reopens as male. So, an avocado tree rarely pollinates itself with its own pollen.* In order for your tree to produce fruit, you must have pollen and ovaries occurring at the same time. Therefore, it must be pollinated by another avocado tree. In botanist terms, there are two different flowering types of avocado or “A” and “B”. “A” is female in the morning and male the next day. “B” varieties open as female in the afternoon and the following morning reopen as male. When the two trees (A & B) meet you have fruit. “A” cultivars: Hass, San Miguel, Semil 34. “B” cultivars: Fuerte, Sharwil, Murshige, Kahalu’u.

Photo by Mari Rand

The question I am most often asked is when to tell when an Avocado tree’s fruit is ripe. Well, you can know the race…or you can judge by a few tricks of the trade. Animals are the best predictors of ripening fruit. Look for the tell tale signs of Mongoose or small rodents that have chewed on the fruit. Dropped fruit is a good indication (unless there is a drought). Size is important and whether or not it seems filled out (like a balloon ready to pop). Whether or not the stem is enlarged at the point it meets the fruit and if it has lightened in color (to a more yellow tinge). Some people look for a darkening of the stem or loss of the gloss of the skin.  Some varieties turn purple or black (San Miguel, Malama Ki, Keona, and Linda). Check for flowers –time to pick. However, the most fool-proof way is to pick one and wait to see when it ripens and what it tastes like. A seemingly ripe but insipid and usually watery avocado was picked too early.

This is all well for the grower of avocados but what about the eater. How do you pick out a good avocado at the market? Most people prefer a ripe avocado but this can often result in a banged up and over ripe fruit (not to mention the five people before you that squeezed it). When the fruit is ripe look for brown spots, bruises or cracks that will result in perhaps ¼ to ½ of the avocado being rotten. Avocados are picked with the stem on (as they ripen the stem may fall off).  When you’re buying them from a random vendor with a box outside their booth look for whether most have the stem on this insures that they were picked not picked up (off the ground). Ask the merchant when the avocados were picked.

If it’s Sunday and they were picked on Friday, plan on not eating them until the following weekend. Avocados take around a week to ripen once picked. My advice is to buy hard avocados that were picked approximately five days ago and be patient. If you want to eat one everyday try putting a few in the refrigerator once they’ve ripened.

Well, I hope this article has you thinking more about avocados, a fruit that is uncommonly delicious as well as…

Well, uncommon!

Our favorite recipe for avocados is to use them in place of olive oil when making pestos. Amazing! If you  have a recipe you like to share, leave it in the comment box. Aloha!

* Which is why avocados are not true to seed. See seedlings.

**Wilson Popenoe, Manual of Tropical and Subtropical Fruits, 1920

Featured photo by Jessica Michie.