It is likely its youth, and also an adjustment to lower light levels. Make sure it does not have mites. You may want to preemptively spray with neem or horticultural oil to make sure. Pics are always nice so we can help you further.

1. It is normal for a citrus tree to discard many of the small fruit. Of all the flowers a citrus tree sets, only about 2 or3 percent will develop into fruit. Even then a certain amount of the imature fruit are normally discarded. New fruitlets compete with one another for the available nutrients, the weaker ones in this fight for nutrition lose out, and are quickly discarded by the tree.. If every flower developed a fruit and it remained, the tree would be crushed under it own weight.

Thanks for the reply. Yes I recognize many are discarded normally. I learned this with my kumquat where many fruit were discarded but a few have remained.

In the case of this eureka lemon tree, none have remained so far. That's my concern. I'm hoping it's mostly just because it's a young tree.

I'd say it's the juvenile age of the tree, here is my in ground tree that's about 3 years old and it's only held onto about 5 fruit so far. Have patience, once your tree starts producing it will have fruit all the time. That's a 6' wall behind my tree for size reference.

Eureka lemon on volkameriana · More Info

Evan