Q.Indoor Lemon Tree
My lemon tree that I started from seed is looking a little tall and spindly. Can I cut the top to achieve a more compact looking tree, or will pruning the new growth hurt the tree?
Yes, you can prune the top stem.
You want to prune so you have many short branches, instead of a few long ones.
Use clean tools to cut the stems. Prune the stems making a cut about 1/4" above a branch union.