Does Your Avocado Have an A Flower or a B Flower?
June 13, 2022
Did you know, there are two kinds of avocado flowers?
Just when you think you've got all your fruit tree information down -- along comes a new twist. Avocado trees are divided into two camps by the kinds of flowers they have: A flowers and B flowers.
Does that sound like Thing 1 and Thing 2 from The Cat in the Hat? The avocado flowers act like cartoons too, with complicated openings and closings and sex changes. Mother Nature had a field day with this one!
Avocados are hermaphrodites (with "dichogamy" for a more botanical term).
Many plants are hermaphrodites, with male and female sexual organs, but avocados are unique because their sexual organs don't function at the same time.UC Davis calla avacado flowers "remarkable" for this trait.
The sexual organs of avocado flowers are active at different times of day (dichogamy). "A flowers" are female (receptive to pollen) in the morning and male (shedding pollen) in the afternoon. "B flowers" are male (shedding pollen) in the morning and female (receptive to pollen) in the afternoon.
For the most part, avocado cultivars have only A flowers or only B flowers. Production is best with cross-pollination between two cultivars, one with A flowers and one with B flowers.
Most avocado plants produce more fruits as they age, regardless of whether they have another plant nearby for pollination. If you live in a suitable climate for avocados, there will probably be another avocado tree nearby. This tree will serve as a companion for your tree for a long time.
"A flower" avocados
- Hass
- Little
- Mexicola
- Stewart
- Cado (has A flowers and B flowers)
"B flower" avocados
- Bacon
- Zutano
- Cado (has A flowers and B flowers)
Best temperatures for avocado flowers
Avocado flowers open and close on a set schedule when the temperature is above 70F during the day and night. Day and nighttime temperatures become a factor for the avacado's decissions. If the temperature drops to 60F during bloom time they may not reproduce at all. A temperature of 65F, though, may confuse the flowers just enough that they gender bend and have both sets of sexual organs working simultaneously.
Avocado trees in containers
Little Cado is a dwarf avocado tree, maxing out at 8'-10' tall, and is your best bet for container growing. Prune it to keep it smaller if you wish. This is the variety with both A and B flowers so you can get fruit with just one tree. You need to protect Little Cado when the temperatures drop to freezing or below.
How to choose your avocado trees
Jump over here to find out which kinds of avocados will thrive in your area. Then choose a combo of A and B trees for your garden or farm. Watch our Growing Avocados video to find out how to plant, prune and harvest these versatile trees. Photo by Cayobo available under a Creative Commons License Attribution 2.0
8 comments
we have a small urban orchard in Santa Barbara of 7 large old trees on a flat half acre and we would like to plant a good cover crop for avocados. Can you recommend a good type of cover crop to use that will provide the needed nutrients and weed abatement. We also have rabbits that live in the field with gophers of course, but we live along the creek so hawks and owls are abundant. Can you recommend a good cover crop for avocado trees, ie., vetch, oat, legume, grasses or a mix ? Thank you – Susan
Jon, you would really have to look at your tree’s flowers at different parts of the day to determine if you have an A or a B flower. The best would be to see if you can find out what kind of avocado you have and that will tell you if you have one with A or B flowers.
I have a single mature Avocado tree. I do not know whether it is an A or B.
I want to plant another to increase its erratic production (some years few, other many).
The bloom season is pretty much past now.
So, how can I determine if mine is an A or B?
If I can avoid it, I really don’t want to have to buy 2 more, to ensure I have a mix.
How and when can I determine whether mine is an A or B, because I want the 2nd one to be the opposite,