I have a four year old pacay in a 45g container. The container seems to be dwarfing it a bit (at least I hope so.). Anyway, I got my first flowers last year and this year I've got a TON of flowers on my containered Pacay. Sadly, I don't believe it's self fertile at all though. I got plenty of flowers last year but not a single pod. This year, plenty of flowers, but nothing appears to be setting into pods either. I saw a YouTube video of a guy in New Zealand who has nice large pacay pods from containerized trees, but he has several trees next to each other. My solution was to buy another small pacay and sadly, wait another 3 years till I get flowers from it too. I'm hoping with two trees I will have pods. In short, you can grow pacay in a large container with no problem. You will get plenty of flowers. However, you will need another tree next to it for cross pollination to set fruit.