Last year, I planted some apple seeds. About 2/3 of them sprouted, and a fair amount survived. However, I learned the hard way that I should not plant trees in the same pot at first, since I was using a cut up water bottle sideways to hold them. So after killing half while transplanting and all but one later dieing, I have the tree in the attached pictures. I know I should probably get a bigger pot, but does anyone know if it's ready to be left out for winter? Since it is the last of the seeds I planted that survived, I don't want to kill it. I can probably find a place inside my house for it if I need to. I've also been fertilizing it periodically with used coffee grounds.