Why does my apple tree drop all of it's fruit early?

Question

I live in Northern California and the tree in my backyard was presumably part of an orchard back in the day. For the last two years, it's dropped all of its fruit while still green. Can anyone help?

Answer 1

Thinning the apples will result in larger, better quality fruit but it won't cure the fruit drop.  That is a stress reaction by the tree caused from inadequate or too much water or fertilizer, climate conditions or disease (age?).  You may want to get a diagnosis from a local nursery.

Answer 2

You need to thin apple trees.  You want a smaller amout of good fruit.  So, when the apples set on, pick off one apple in each clump.  As they get larger, remove apples so that your fist can fit between remaining apples (approx. no closer than 4").  Continue thinning throughout the year and enjoy your apples.  

Since, this year is a loss, make sure and prune your tree heavily in January so it will again produce less fruit, but quality fruit.

Answer 3

Not enough water.  Fruit bearing trees need plenty of deep watering from flowering to produce fruit.  Once a week is enough during the growing season. Your tree is setting fruit but hasn't had enough moisture to continue the growth on and has thrown it.

Pruning will help for better fruit production, but you are getting fruit just not keeping it.  Easily fixed give it a good fruit fertilizer in spring to get it nice and healthy and lots of water and you should get some fruit.