My two year old son wanted to garden with me (I've got a couple pepper plants and some spinach growing under lights in the basement) so I asked him if he wanted to grow food, or a flower. He was very insistent on a flower. The only thing I could think of was some saffron seeds I bought off of amazon. Turns out saffron doesn't seed, so they're b*stard saffron, or safflower. I was reading they have a large taproot. The thing is currently about a month old, six inches tall, in half of a milk jug which is pretty shallow. What could I transfer it to so it doesn't stunt the growth as much? Would a two liter bottle be sufficient, or does it also need to be wide as well? I'll probably move the thing outside in the spring if it makes it that long.