Kinda.

Cultivars of avocados have two different kinds of flowers, usually called simply "A flowers" and "B flowers". Some cultivars have only "A flowers" and some have only "B flowers".

"A flowers" are receptive to pollen in the morning and shed pollen the following afternoon while...

"B flowers" are receptive to pollen in the afternoon, and shed pollen the following morning.

Consequently from a technical standpoint, production is best with cross-pollination between two cultivars, one with type A flowers and one with type B flowers.

But the reality is, most cultivars of avocado seem to get better and better at producing furits as they get older, another pollinator or not.

And 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 in the next many years.

By the way, 'Hass' has A flowers. And most trees in 5-gallon cans or larger will prodcue a few fruit the following year.

Joe

Thanks Joe. I don't know of any avocado trees in this neighborhood. What are type B flowers? Would a Fuente avocado be a B type?

B flowers:

'Bacon'
'Fuerte'
'Jim'
'Zutano'

Others with A flowers:

'Mexicola'
'Pinkerton'
'Reed'

Joe

Thanks so much Joe. I will try to plant a Fuerte near my Hass.

from Dave Wilson Nursery says the A and B flower types are only applicable in a tropical climate. And that in our climate the flower opening time is not distincly morning or evening for A or B. I can see it being important to maximize production in a commercial orchard setting. But a home garden tree will produce far more avocados then you will know what to do with, even on a bad year!

Here is a link that might be useful: avocado

I had several hundred non-Hass trees and grafted them over to Hass about 3 years ago. They were originally planted as pollinators and sat among thousands of Hass trees in a commercial grove.

I have seen no degradation of production since their conversion and continue to set much more fruit than the tree can carry to maturity.

I suppose each location is unique based on wind, moisture, temperatures, etc.... but I often see male and female flowers open at the same time here in southern CA.

Based on the number of blooms available per tree, it doesn't take a large percentage of successful pollinations to maximize the trees fruit capacity.

Thanks everyone for taking the time to answer my question. I feel lot more confident about my avocado tree producing even without a B type of tree.

how close to each other do the trees need to be planted ?

They can be one on one side of the street- the other on the other side. Like Joe said above..funny they make more fruit the older and larger they get. You only have to make sure you are planting a grafted tree. Seedlings can take from 7 years to 30 years or never.
btw- I did have a seedling produce at 7 years the best and largest Hass type I ever had. Then 3 years into producing...it died.
I have a dwarf Mexicola..the older it gets..etc. Fruit are ok if small.

How exciting!! my mother's Hass has produced fruits the following year after she got it and planted it in ground. This is her 2nd year with fruits. I also just picked up my very first avo (Sharwil) and this type is supposedly self producing, if not there will be a few avo trees within a block or two from our house to pollinate it. We're in CA, lots of avo trees around, I think we'd be ok.