Does Your Avocado Have an A Flower or a B Flower?

By on October 10, 2013

An avocado tree in bloom. Those flowers have a gender-bending life.

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” if you want to sound botanical)

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 calls the avocado flowers “remarkable”.

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. But the reality is, most cultivars of avocado seem to get better and better at producing fruits as they get older, another pollinator or not. If you live in a good avocado growing climate, there’s almost invariably another avocado tree in the neighborhood that will be your avocado tree’s buddy for many years.

“A flower” avocados

Little Cado (has A flowers and B flowers)

“B flower” avocados

Little Cado (has A flowers and B flowers)

Avocado flowers are like everyone else, happiest when the temps are in the 70s

Avocado flowers stick to their complex schedule of opening and closing as long as the daytime and nighttime temperatures are over 70F. 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.

The avocado for 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

Leave a Comment