Thought I'd throw in my two bits worth, since I've killed more than my
share of avocados.
The pit needs to be thoroughly washed in soap and water, then rinsed in
clean water and dried with a clean paper towel and left to dry for a day
or so. Any loose brown outer skin can be peeled off, but be careful not
to damage the flesh underneath. All these precautions prevent growth of
mould, etc, while the pit sits in water for the month or so it takes to
break dormancy. Boil water in a kettle for 10 minutes, then pour a glass
full and suspend the pit, pointed end UP, about half-way into the water.
Roots grow better in the dark, so wrap the glass in aluminum foil. This
also prevents the growth of algae.
Set the glass on top of the fridge and add water as it evaporates. Never
let the pit dry out. When the root appears plant it in potting soil or
peat moss and set the pot in a pan of water. Cover the whole pot with a
plastic bag, since the shoot dries out very quickly. Avocaado needs lots
of light and heat, and a high humidity The brilliant, shiny new leaves
will drop off as soon as they appear if you don't keep it covered or
misted often. Don't uncover it until at least three or four leaves are
emerging in a group. At this point you have a fighting chance of
repotting it in a large pot. Fertilize and water the hell out of it. It
will grow as large as you want it to, but needs lots of full sun. Mine
has its own grow light and is presently one year old and four feet tall.
...Paul from the Great White Northeast