I just planted two 36" box California Peppers (Schinus Molle) in my back yard. One is a multi trunk, that I'm planning on keeping that way. The other is structured more to be a beautiful single trunk, but it has one "odd man out" additional small trunk about 2-1/2" - 3" in diameter. (See photo)
In the long run, I'd prefer to cut that sucker off at the base. My question is how long should I wait? Is there a risk of shocking the newly planted tree if I do it now? Would I be better off to wait until late winter/early spring before the next grow cycle? I hope I can get rid of it at some point, and train the tree into eventually a shade canopy that can be walked under.

Thanks in advance for any advice!
Chris