Q.My nectarine trees
Why do the blossoms fall off my nectarine trees? I never get any fruit.
Nectarines do not need a pollinator so the reason your tree is not setting fruit is most likely damage from cold or frost, pests, disease or an unhealthy tree.
Trees can be covered when temperatures are expected to drop.
Watering the tree well the day before an expected cold spell can help.
To protect from insects you can spray the tree in winter with a fixed copper fungicide or Neem oil. Respray just before blossoms open and then again in late Fall.
Keep a good watering schedule for the tree. Watering once every 2 to 3 weeks approx 2 to 3" of water.
Fertilize in Spring when the tree just starts to grow with a high nitrogen fertilizer. Follow package application directions.
Fertilize again in the Fall.