Inserted is the link to an avocado tree seller in Florida, maybe it's near you? They may offer scionwood, or maybe you could just buy a tree from them. Carla in Sac And here is another link to the story behind the Hass mother tree: http://www.avocadocentral.com/hass-variety/hass-mother-tree Here is a link that might be useful: Tropical fruit nursery avocados

The first photo looks like 2 trunks, so I'm thinking you have a seedling tree. You can top work the tree by grafting a good variety on it. There are a few good You Tube videos showing exactly how to do it. I plan to do this with my seedling that isn't as old as yours, but pretty aggressive.

Skyvok, I'm guessing that's their cold hardiness zone. The USDA has a set of number zones with specified minimum temp ranges to help gardeners and growers find plants that will survive winter in their regions. I'm in zone 5b and my winter extremes lows can get in the -10 to -20 F range, so looking for zone 5b on plant labels helps me find stuff that will come back in spring.

No and yes in that order. I live on the Alabama side of the Gulf Coast. If your advanced enough in gardening and are used to covering things like certain citrus or using heating cables, lamps, wood burning barels, heaters with fans, christmas lights, or any similar method of keeping them heated then by all means. I have grown them a couple of times and it seems every couple of winters I forget and have to go back to the beginning. I still say it is worth it by far and honestly we have only had three days of frost this winter so far so covering with the tarp was pretty easy. Hope that helps a lot.