Question
I have a giant dumbcane indoor plant that has been doing very well until recently.  It is getting too top heavy.  There are three in a giant pot.  The leaves have been taken off the bottom of the plant stocks and it is starting to warp downward due to the weight of the top leaves.  I would like to cut it down and maybe get more sprouts off each stock.  I am wondering the best way to do this.  Where do I cut and how should it be handled?  This plant used to be close to 9' tall and is now warping down to 6'!  So I need help.  Thank you.

Answer
Hello Leslie,

Before you do anything at all with this plant you need to know that it抯 very very poisonous. If ingested the sap can cause the tongue and throat to swell resulting in suffocation. So make sure you wear gloves and thoroughly wash any tools after you work with this plant.

Now that we have that out of the way, it will be easy to fix your problem. You could cut the plant down to the desired size. Make sure there are nodes (they'll look like little bumps) left on the plant. New branches will grow out of these and the plant will continue to grow.

The other route you could take is to propagate a new plant and start from scratch using air layering or cane cuttings. There is a chance that the mother plant won抰 recover and these new plants could be a backup.  

Cane cutting is a little bit easier than air layering but doesn抰 have the reliability of air layering which allows the plant to develop roots before it is put into the ground. However, it is easy to take multiple cane cuttings ensuring that at least some will survive.

Cane cutting is about half way down the page.
http://www.hort.purdue.edu/ext/HO-37web.html

Air layering is a little more time intensive and complicated but the new plant will already have roots when it is planted in the ground giving it a better chance of surviving.  

http://aggie-horticulture.tamu.edu/extension/ornamentals/airlayer/airlayer.html

Remember to dispose of any left over plant matter so that children and animals can抰 get to them.

I hope this helped.

Good Luck,
Justin