Fruit bearing tree from store-bought avocado's?

I've been planting the seeds from all avocado's that I buy and eat. Since a month or 2, 4 of them have grown into young trees. Someone recently told me that they will never bear fruit. Can someone confirm or deny this? If there is no possibility that they will bear fruit, I want to buy some trees that will, rather than waiting a couple of years...

Hi Philippe.

My much better half and I grow our avocado pits out. We are in Toronto, Canada, so our oldest, while four years old already and taller than me with multiple secondary and tertiary branches, has yet to flower.

The reason this doesn't matter is that you're likely to want to find scionwood of a cultivar that you enjoy anyways, and graft that onto the best, most healthy plants you've grown yourself in the place the trees will continue to grow and mature.

Don't get me wrong. I don't think it's a doomed effort. But it's not a waste if they don't fruit. You're still growing tree infrastructure, and for cheaper than buying a live tree. Even the scionwood will be cheaper than buying a good-to-go, probably grafted, nursery tree.

I should probably ask: where are you? Also, are these to be grown out in the ground, or is it, for the moment, a potted tree project?

Pictures are always appreciated. Let us know how it goes, and good luck!

-CK

Store bough avocado will bear fruits and lots of it.
Avocados are self-fertile and so it does not need a pollinator.
They grow true from seeds similar to peaches.

I am not sure if you are in the tropics or in USA.
If you are in USA then I recommend that you avoid the bigger smooth skin avocado and focus on one of the smaller dark rough skin (Mexican) avocadoes
Persea americana var. drymifolia
https://onegreenworld.com/product/mexicola-seedling-2/

There's another option:

Grow out the Avocado pits and then graft scions ( cuttings ) from your store bought tree onto them. I have no experience with avocados, but I grafted apples for the first time last spring and had 100% success. I'd suggest you follow the examples that you google or watch a video like these. You can google "whip and tongue grafting" to get an idea of what you need to do. I used a retractable safety knife and bought grafting tape on eBay for a few bucks which included the shipping. I used plumbers teflon tape to seal the tips. They sometimes use wax to seal the tips. If decide on the wax you can find it at your supermarket if you ask for "Gulfwax". I think it was $5 for a box about the size of a pound of butter. When I graft again I'm going to cut a hole in the bottom of a half gallon milk jug and use it as a hand guard when I cut the tongue into the two pieces I'm grafting.

You can reproduce your trees this way for zero cost.

From what I've read, if you grow a Avocado from seed it won't produce any fruit for at least 10 years, and probably closer to 15 years.  It's kind of a crap shoot whether or not the fruit will taste good.  

As the others have pointed out, if you graft a scion from a tree that produces tasty fruit then you'll get tasty fruit and it will possibly start producing after only 2-3 years.

The avocado is a fruit, all fruit trees take at least 7 years to bear their first fruits, that's why most nurseries sell trees that are older than 7 years from sprouting. (I specify 10 year old trees to my nurseryman when we are buying new trees for the orchard)
The Hass avocado is probably one of the best for growing in the USA, it has been acclimated to the USA for over 100 years.

My best tasting avocado is a seedling tree. My understanding is the avocado is not sufficiently selected to grow anywhere near true from seed reliably as happens with some fruit that have been selected for many seedling generations. Most avocado cv.s are selections straight from the wild. However some do produce quite close to the parent tree, the best tasting fruit I mentioned is seedling of 'Reed', and tastes and looks similar, but subtly better flavour.  This one also produced fruit in much less than 10 years, possibly only 5 (can't remember exactly). The major problem with avocados is flowering season. If you live in a place with a proper winter season, you need an avocado that does not flower in winter. Pollination is generally considered to require a 3 day period with days above 17C and nights above 12C for any fruit set. If your tree flowers in winter and you are colder than that, you get no fruit. This is one of the reasons why 'Hass' is so popular, it flowers in spring. Hass replaced "fuerte', which  is a more cold-tolerant tree but flowers in winter so pollination is more problematic. I have one avocado seedling that fruits massively in mid-winter and produces no fruit.

As a native South Floridian, though I no longer live there, I've personally witnessed many seed grown avocado trees. They usually produce an acceptable fruit at the least to a fruit not far from its parent. They can take 7-10 years to fruit in many cases but I've seen seed grown trees produce in as little as 3 years. It is a bit of a possibility it could take a long time or have unacceptable fruit but more than likely it won't be a waste of time. If you don't like the fruit or cannot wait 7+ years possibly then graft a few branches and it'll be all good from there regardless.

i am growing avocado seedlings in a less than ideal environment so time to fruit takes longer
physically how do the trees look once flowering size?
one of mine stayed short and grew more lateral so it could be haas
the other shot for the sky and has been topped
it has grown lateral branches now and has a thicker stem than the other
half an inch diameter maybe
i have years to go i would expect but just wondering abut the size of a fruiting tree  

http://bigislandnow.com/wp-content/uploads/2015/06/AvocadoPoster.jpg