I've read previously about using multiable trees to help fast grow a trunk. With no previous experience doing anything like this, can someone give me a rundown on how its done. I have 3 seeding junipers that I would like to use.
You can use multiple trunks to create a single trunk, however, much depends on the species you're working with and what you hope to accomplish.
"Fusing" multiple trunks into a single one depends on the particular species. It's usually done with fast growing (relatively) species like trident maples and tropical species like ficus. Junipers,however, aren't fast growing and success with them using fusing techniques aren't nearly as succesful, nor as quick.
Whereas a bundle of seedling trident maples might fuse in a few years and tropicals in six months, junipers could take quite a bit longer.