It's been years now. I think we have had it for nine summers. It's a big tree. It was supposed to be a Titan female. We also purchased a no-name male. We have thus far NEVER seen any berries or fruits on the female. EVER. We don't give any Nitrogen, as we were advised by the nursery we purchased it from, not to. Still the same result. Anyone have any experience with this?
They don't grow down here but from what I have read they need full sun, will not tolerate shade from larger trees near them, the male must be planted upwind of the female since the pollen is windblown and they should be no farther than 5-8 feet apart so the pollen can reach the female. And it should only take 3 years from planting for them to produce berries. Have you contacted the nursery you bought them from to see if they have had other growers reporting this problem? You are correct about not feeding them nitrogen, they are a nitrogen fixing plant (much like legumes but they are not in that family).