I have a Dieffenbachia Tropic Snow since the mid "70's" and its been topped off and sprouted in water and replanted several times sucessfully. I have recently topped it off and heads are sprouting well in water. I've also cut some of the cane back and have 12 sprouting in pots.
I have 2 questions;
1- in the original pot i still have 4' foot canes that have started to re-sprout, about 1"inch out now. "CAN I CUT BACK THE TOPS WITH SPOUTS ABOUT ANOTHER 12" and resprout? Or will it be too much shock for the plant growing from both ends?
2- over the years my Diefs cane have reduced in diameter...
How can i grow bigger cane? They used to be up to about 4" in diam and now they barely grow to 3" inches ??
Hope someone can help me with this.
Thank you for this great website !!!

It sounds like you're having a blast with your Diefs! Sounds like the bigger kind (than the usual suicidal little 'Camille' ones that are so often seen at BBS's.)

I would let the top part get some significant foliage, then definitely cut again if you want.

If you are able to share some pics, I'd love to see them!

If I understand correctly, you now think you should have cut back the stems closer to the soil. If so, you can re-cut at any time. The new growth on those stems will probably survive your attempts to propagate them. Next, time prune all the way back to within a couple of inches of the soil right from the outset.

The thickness of the stems depends on the available light at the time that part of the cane is first growing. The original canes were grown in ideal greenhouse conditions with optimal light, which is impossible to duplicate in your home. If you improve the available light, new stem growth will be thicker going forward.