So I'm growing some trees from seeds. How can I thicken the trunk of the trees an is there a way I can keep this tree short. What methods to use.

That is a whole bunch of questions! Loads of roads. All com down to.. get lots of groeth on the plants. Fastest is to.plant them.in the ground for anfew years.

Have a read www.growingbonsai.net/growing/trunks/