Question
QUESTION: Hello,
can I pollinate my pistachio tree artificially?My tree bears nuts that are empty.The trees are 10+ years old.
Thanks

ANSWER: Dear Chris, Theoretically yes, but practically probably not.  You would either have to have a huge supply of pistachio pollen or have a pretty good supply and meticulously hand pollinate each female flower at the right time.  The best thing to do is to just buy a male tree.  It doesn't need to be a very big tree, just big enough to flower.  One male tree can pollinate  8-12 female trees.  Incidentally, pistachios won't actually produce nuts until they are about 10 years old.  I hope this information helps.  Please let me know if you have further questions or have difficulty locating a male tree.  Good luck, Melissa

---------- FOLLOW-UP ----------

QUESTION: Hi,
I do have a male tree and nuts are still blank.
Thanks

Answer
Dear Chris, I did a lot of searching and I'm still not sure I know why your tree is not producing.   Here are some suggestions.  You can prune a branch of a male tree ONTO the female tree and it will pollinate the tree that way.  That would be one way to guarantee that the pollen was available when the nut flowers were ready to be pollinated.  If you don't know how to do this, you could contact your local county extension office and they probably have a fruit and nut committee who can possibly even do this for you for free in order to show you how or maybe for a small fee.  In addition, the extension office will likely have more specific information on pistachio trees: growing tips, spraying schedules, and more useful information.  The pistachio tree is one of those nut trees that is often bearing every other year, with barren or sparse years in between.  In addition the nut harvest is affected by drought, high humidity, too much rain or heat and winds.  So I would recommend that you probably go ahead and graft a male branch to the female tree (you may not be able to do this until the trees are going dormant), and contact the extension agent in your area for grafting information and spraying schedule.  Good luck, Melissa