Question
I live part time in the US Virgin Islands and have gotten locally grown Avocados that I'm using the seeds to propagate. I do have one plant that's about a foot and a half tall. I'm now growing another from seed and it has at least tree stems coming out of the seed. Is this normal? Is it three separate plants? Should I plant it as one plant? Thanks

Answer
Hi Joseph,
Thanx for your question.  The situation you describe is a polyembryonic seed meaning the seed has more than one embryo inside of it which would result in two or more sprouts.  One of the sprouts is the sexual embryo and the others are asexual.  Sometimes the sexual embryo will die and the two asexual embryos will die.  I would let all three grow and see which ones survive.  The sexual embryo is the result of cross-pollination and the resulting seedling will bear qualities of the mother and father trees.  The asexual embryos are a product of the maternal seed tissue (the seed is from the ovary of the mother plant) and the resulting seedlings will be clones of the mother.  If the mother tree has desirable qualities, you will want to nurture these seedlings.  The sexual embryo will be variable in qualities and you may not desire to keep this one except as a house plant or as rootstock material.

So, what you have it appears is three seedlings.  One or more may die naturally.  Allow them to get large enough to separate and then you can do that with a sharp, clean knife as you are able to determine the individual root stocks.  Or, as they get larger and all three survive, trim off the undesired plants, leaving one growing.  Polyembryony is common in citrus and mangoes and not so common with avocadoes but common enough that there has been extensive research done on it.  The University of Florida and the University of California-Davis both have extensive information on growing avocadoes.

http://edis.ifas.ufl.edu/mg213  University of Florida
http://www.californiaavocadosociety.org/growing.html  California Avocado Society  with links to UC-Davis.

I hope this helps.
Tom