There is at least one cultivar of Avocado that is more dwarf, but the species in general doesn't lend itself to container growing long term. At the very least, it will prefer something as large as an oak wine barrel for size, do you have that kind of room on your deck? It will grow for several years in a 15 gallon sized container, but is unlikely to give you any fruit restricted to a small pot like that.

I have a Brogdon in the ground and it has done well with no damage from our recent cold winters. Mine is about 20' tall but I understand you can keep it trimmed back and it will still produce. I also have a Haas in a planter that I can wheel inside when it gets cold. Either should do you well or you can get a true dwarf and try that: http://shop.tropicalfruit.com/Wurtz-Dwarf-Avocado--3-Gallon--GRAFTED_p_141.html Enjoy. Nothing tastes better in your salad than a fresh-picked avocado.

i grew a 3ft avocado tree from a pit. it was doing great while i lives in california then i moved out to nebraska and within days all the leaves fell off and died and now the tree just sits there looking like a skeleton. when i 1st got to nebraska it was below freezing so i kept it in the garage, then it looked like it died now the temp is up and iwater it and it gets tons of sun everyday and still nothing. and also all over the tree, like on the branch times there is some sort of white powdery stuff. what is that? did my tree die? or isthere something i can do for it???

Leave a small part of the seed exposed just above the soil line (maybe about 1/2 inch. Now, you understand this will be just a fun thing to grow...not for fruit production. If you want this to become a fruiting tree...you must graft your desired scion to the top when it get bigger.