The plant was no more than 2 inches tall and had cute little palm leaves at the top. This sucker grew to over 7 feet tall and it must weigh over 75 pounds. I have to lug it outside every summer and lug it back in in the fall. One year it fell on my head (see previous entry). I use to replant it every couple of years, but I stopped doing that when it became too heavy and painful to hold. I just throw some leaf mulch in the pot each year to replenish the soil. Actually, after reading about this cactus, I'm surprised it grows at all. I don't have it in sand or cactus soil and I never have. It's just regular old plant soil for this thing.
This year I decided to cut off the top. I read that was the way to prune them. They even said you could plant the top and it will root. We'll see. I won't be sad if it doesn't work because heaven knows I don't need two of these monstrous things to lug in and out of the house.
What I learned in my internet search is that this plant is related to the plumeria (or frangipani as they say in Florida). If you read my Key West blog, I fell in love with the smell of frangipani. This plant blooms in warmer climates and smells like frangipani. It won't bloom here because it goes dormant in the winter when I bring it inside. It prefers the tropics, like me.
UPDATE 7/13: It's working! The trunk is spouting branches all around the cut. There's about 20 sprouts.
And the top is doing just as well. I don't know if there are roots yet, but it's not dying as the leaves keep getting bigger. Two smaller plants will be so much better than that one large monster plant!!
UPDATE 2013: It worked, 2 years later, and both top and bottom are growing like champs. I hope that now that they are growing in shoots they won't get to be 7 feet tall again.