How & When Does One Prune a Growing Avocado Stalk?

Question

It gets leggy before the leaves come out on the stalk. It is in dirt in my window that gets indirect southern sun.

Also, how deep should it be planted? How wet should it be kept?

Answer 1

If it is getting leggy, it is likely not getting enough sunlight. I would recommend moving it to a brighter window or supplementing the light with a plant light or a fluorescent lamp.
 
As for pruning, this article will help:
https://www.gardeningknowhow.com/edible/fruits/avocado/pruning-avocado-trees.htm
 
If you already have it in dirt, how you have it planted should be fine. If the seed is showing above the soil, this is ok, or it is ok if it is not.
 
Water it when the top of the soil is dry to the touch. I tell people not to water on a schedule, but rather check the soil on a schedule and only water when the top of the soil is dry.