I agree with Dave, not the season to do this, but then again, we have no idea of where you are on earth, and it matters, even indoors. I did this in here in NJ back in June as my HUMID summers make it risk free. They do a natural tendency to get leggy as they try to reach toward the light in a shady rainforest. In the meantime, stake it with a few bamboo poles, you are the boss, not your Dieffenbachia.

Agree that you could cut off stems and stick them in water to root, or back in the same pot right after cutting. But you don't have to do anything if you don't want to. Maybe put the pot on a pedestal so it has more room to dangle. Agree, it looks perfectly happy, and beautiful, as a not-upright plant.

In a more bright spot, the growth goes straight up.

Thank y’all for your advice! We are in South Louisiana…it’s humid and warm through Christmas. He has been on my patio for the past 3 months as we were renovating. I have him in a tall container even though it doesn’t look so in the pic. The limbs have grown so much and now hang to the ground. I love the whimsical look. Is it ok to just cut at a particular part and root? He’s back inside now (ac temps linger around 73). Should I cut and move back outside until frost?

These are extremely tropical plants, in NJ, mine come in by mid-late September just to acclimate to the indoors. Yes, sure you can leave it out later in S. Lousiana, but I would move it back inside already. Yeah, I still have a LOT of my real tropicals still out..., papaya, mango, philodendrons, Monstera. Got a lot of work to do, as always!

Do you think it’s to late to cut and root?

propagate cuttings.. yhou can probably make 100 plants out of that one...

and then just get rid of the old monster ... its not really doing as well as you think ... its ok.. just not great ...

small plants are better in smaller pots... no one knows why ... so work your way thru pots sizes... until the plant is big enough for your old pot... you can always stick smaller pots in your larger pot.. if you want ...

if you want to reuse the old pot.. its probably a good time to start will some fresh media... i prefer promix bx ... the medium.. is the most important thing in the pot... so invest wisely ...

watch a bunch of these.. to see how easy it is...

https://duckduckgo.com/?q=Dieffenbachia+propagation&t=ftsa&iax=videos&ia=videos

for me up north.. this would not be the best season.. but due to how far south you are...so much closer to the equator.. and the fact that your sunlight doesnt dim as much as mine.. i dont know why you cant go for it now... the worse that might happen.. is it takes longer ...

since you have many stems.. there is no reason.. you can cut one down... and try that.. leaving the rest as a failsafe...

ken

Yes, you can cut off any single stem and leave the others alone. You don't have to have a "pruned" appearance if you want to approach it in stages over time.

Any time when it is not too hot and dry is a fine time to propagate this plant, IME with it.

Cut it. why would you want a plant when you can have plants

I have to share a personal experience with you; you can propagate your plants in any season; just take good care of them after propagation. I propagate plants at home throughout the year. Just don't be afraid.