I started an Avacado tree from a seed a few months ago by using the toothpick in water method to suspend the Avacado over the water until it sprouted. Since then I have purchased some potting soil and placed the pit 3/4 of the way in the soil.
Now it goes through a cycle where it will produce 3 nice large healthy leaves, then in about a week they start to look wilted and then starting at the tips back they turn black and die. I then pinch them off and then the plant produces 3 more nice healthy looking leaves and the cycle repeats. It has done this 4 or 5 times now and the 'trunk' has gotten a bit longer.
I am not sure what I am doing wrong and I was hoping that someone here could tell me how to make this a healthy plant.