Question
Hello,
My Pistacio Tree has nut shells with no nuts in them at harvest?The trees are 10 years old and no nut in the shell at harvest. This is 4-5 years now.
Thanks

Answer
Dear Chris, I actually had to do quite a bit of research on pistachio trees in order to answer your question, which I had been planning to do for some time.  Ok, there are several factors involved here.  First, the pistachio tree will not actually bear fruit (nuts) until it is seven to ten years old.  So since your tree is 10 years old, it is just at producing age. However, I feel certain that the reason you have no nuts in the shells must lie with the lack of a male tree.  Interestingly, (a fact I didn't know), pistachio trees are either male or female.  So since you have a female tree, you will need a male tree nearby to pollinate it.  One male tree can pollinate from 8 to 12 female trees.  Now, I am assuming that you don't have a male tree.  Not to worry, just get a male tree; it doesn't need to be a very big tree, just big enough to flower.  Now if you DO have a male tree, then I would think that the problem is one that involves spraying.  Fruit and nut trees generally are sprayed according to a schedule that addresses both insects/diseases and fertilizing.  This schedule can be obtained by a county extension (or agricultural) agent.  I hope this information helps.  Please let me know if you have further questions.  Good luck, Melissa