How to handle grapefruit seedlings
My girlfriend gave me four grapefruit seeds she obtained from a grapefruit she ate. The mother plant was planted in the 1930's or even before and from what I know of its origins it is probably not a commercial hybrid. I managed to germinate all four seeds. I gave one of the seedlings to my mother-in-law when it was a year old and about 6 inches high. She managed to kill it. However, I still have the the other three growing in containers.
They are now two years old and about two feet tall. Last year one of them even flowered, but there was no fruit. My questions are:
1. At what point do I cut the tap root? I expect to keep these in containers for life.
2. Do they need to be topped or pinched or otherwise pruned? Even though they are growing well, they aren't really branching in any way. Will that happen later? Right now growth is strictly upright. One of them has a branch bear the base. The other two are single stems. The mother plant was well-branched in form.
3. Is there anything else I should know about growing citrus from seed in containers?