On May 5, I posted a video titled, “California avocado superbloom 2023.” In it I showed a large Gwen avocado tree that looked like a massive yellow ball of flowers, and I gave my thoughts on why this tree and some others I had seen around Southern California were having such an intense season of flowering.
And I wondered whether the pollination of these numerous flowers would follow. If you don’t mind me quoting myself: “I suspect the fruitset won’t be quite as spectacular as the amount of bloom.”
So what happened? How has the pollination of California avocado trees turned out this spring of 2023? It is here in August that we can begin to take account, as few fruitlets should drop after August.
Overall, the fruitset is a mixed bag, both in my yard and throughout California, as far as I’ve seen and heard. From the mixed results I’ve tried to tease out patterns and explanations.
Ocean proximity hurt?
The main pattern that I’ve noticed is that avocado trees close to the ocean have worse fruitset than trees inland. Last week I saw many Hass groves near the ocean in and around Carpinteria that have terrible fruitset. One grower there said he hadn’t seen pollination this poor since the early 1990s.
On these trees at the end of July you could see the stems of all the flowers still hanging, but without much, if any, fruitlets attached.
Growers in this area said that throughout May and June there was incessant fog. The flowers simply were not being visited by many bees because bees don’t like to fly in that weather, not to mention that the high rainfall had caused extra flowering among the surrounding native plants which are more attractive to many kinds of bees compared to avocado flowers.
On the other hand, a couple days ago, I saw groves of Hass trees at Cal Poly San Luis Obispo that had good fruitset, but Cal Poly is far enough inland to not be ensconced in fog like in Carpinteria.
A farmer in Ventura County that I spoke to said his grove of Hass trees that is not too far inland has fine fruitset, and he thinks it’s because he girdles his trees and the girdling helps the flowers set fruit.
I’m inclined to believe him because my own Hass tree that I girdled also set a fine crop.
Honey bees overrated?
Each year during avocado bloom I take frequent walks among my trees to observe who is visiting the flowers. This year I saw almost no honey bees, but I did see various flies and some native bees on the avocado flowers. This observation worried me because it is a common belief that avocado flowers in California need visits from honey bees in order to be pollinated.
But this situation also gave me a chance to test the claim that honey bee visits are necessary for pollination. If my trees ended up with good fruitset despite the lack of visits by honey bees, then that common belief should be discarded; that is, honey bees are not necessary for good avocado pollination.
You already saw the good fruitset on my girdled Hass. I got good fruitset on most other varieties in my yard that had lots of flowers this spring too.
My conclusion: Honey bees are overrated as avocado pollinators. While they are good avocado pollinators, they are clearly not necessary, nor are they the only good avocado pollinator.
B types worse than A types?
Yet I do not have good fruitset on all of my trees. One of my Edranol trees flowered profusely.
And yet today it has only two young avocados growing on it.
Edranol is an avocado variety with a B type flower, which means its flowers don’t function as well in cool weather compared to A-type varieties such as Hass and Gwen. That is my explanation.
In general, in my yard, the A types set fruit better than the B types, and I think this is because of the cool spring weather.
2023: rainy winter, chilly spring. How will the summer weather end up?
And how is the fruitset on your avocado trees? Can you explain the results? More ideas can be found in my post, “Why no avocados on your tree?”
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