Q.Avocado plant grown from seed.
Hello there!
While I was at university, I started growing an avocado plant from the pit of a supermarket avocado I had eaten. It was a fun experiment and it’s still alive almost two years later and doing very well!
It’s probably now around a 2.5 feet in height, lots of leaves, and has 3 new branches (plus a tiny set of leaves at the very base of the plant). Overall it looks very healthy from my naive gardening knowledge!
As just a bit of extra information – I live in Exeter, United Kingdom. I think it’s hardiness zone 9a (ish). I’m guessing its a Hass avocado as that appears to be pretty much the only avocado type that’s sold in the supermarket. It’s currently grown in a 25-30cm pot. It’s outside during the summer and I bring it inside for winter.
Basically, I keep reading online that a avocado grown from a supermarket avocado pit will never flower / produce fruit? I don’t really mind – its a fun experiment anyway and its quite a pretty plant.
But I was wondering what is the reason for this, and whether there was any way of helping it produce fruit?
I read three reasons as to why, and I was wondering which was correct? Or a different reason altogether!
1) Avocados just have to be grafted. And no amount of good climate/gardening will make a shop bought avocado bear fruit as its just genetically impossible.
2) Avocados have to be at least 10 years old to bear fruit and a shop bought pit will just never get to that age without dying. If so, then why is that the case?
3) The UK just isn’t a good climate for avocados, and so will never bear fruit.
If there is a chance it would bear fruit – is there anything I could do to help?
Sorry for the long question!
Thanks very much!

This article will help you.
https://www.gardeningknowhow.com/edible/fruits/avocado/avocado-tree-growing.htm